Formal approaches

Formal approaches explore the outcome of rational decision-making with regard to choices faced by prehistoric populations. By conceiving of economic behavior in terms of universal rationality, these approaches are analytically useful because they allow for the isolation of variables and for cross-cultural comparisons. Formal economic analyses are built on studies of modern markets by human geographers and involve reducing labor, land, and capital to the price as the unit of cost. Anthropologists using formal approaches may apply energy or time as value units to studies of food procurement, raw material provisioning, and settlement choice as in studies by behavioral ecologists (Winterhalder and Smith 2000) and archaeologists (Earle and Christenson 1980;Jochim 1976;Kennett and Winterhalder 2006).

Formal approaches to prehistoric exchange have been used by archaeologists to study the evolution in exchange systems both organizationally and from the perspective of individual behavior (Earle 1982: 2). On the larger scale, regression analysis (Hodder 1978;Renfrew 1977;Renfrew, et al. 1968;Sidrys 1977) and gravity models (Hodder 1974) use assumptions of cost minimization to differentiate between possible exchange systems in prehistory. "The sociopolitical institutions establish constraints in terms of the distribution and value of items. Then, individuals, acting within these institutional constraints, procure and distribute materials in a cost-conscious manner" (Earle 1982: 2). Neoclassical assumptions on the scale of individual behavior have also been used to examine the evolution of market based exchange (Alden 1982) and subsistence goods exchange by territorial groups exploiting high-yielding yet unpredictable resources (Bettinger 1982). A synthesis by Winterhalder (1997) investigates the way in which complex exchange behaviors that have been documented ethnographically can result from models of circumstance such as tolerated theft, trade and risk reduction, and models of mechanism such as kin selection and dual inheritance.

Critiques of formal approaches have been various, with strong methodological criticism coming from influential ex-formalists like Ian Hodder. On the subject of exchange, Hodder (1982: 202) observes that the explanatory power of formal approaches to prehistoric exchange are significantly weakened by the problem of equifinality in the empirical evidence, an issue discussed below. Hodder further argues that middle range links between social contexts, political strategies, and the empirical evidence provided by distributions of archaeological data are insufficiently accounted for with formal approaches such as regression analysis.

Substantive approaches

Substantivism arose in anthropology largely in response to what was perceived as the inapplicability of formal approaches and the assumptions of neoclassical economics to ethnographic case studies (Wilk 1996: 1-26). Substantive approaches emphasize that economy and exchange are fundamentally linked to other aspects of human behavior. To substantivists, economic institutions are effectively cultural traits, therefore techniques designed around "modern" or "western" conceptions of rational individualism are inadequate for application in non-western cultural contexts (Bohannan and Dalton 1962;Dalton 1969). The position was first articulated by Karl Polanyi (1957) that the economy is "embedded" in sociopolitical institutions. This view of economy and non-western exchange has its roots in studies by Malinowski (1922) and Mauss (1925), although the focus in that earlier period of economic anthropology was on social relationships, whereas social change dominated the discourse in economic anthropology during the 1960s (Dalton 1969).

Mid-twentieth century substantivism was based on a functionalist view of society as static and aspiring to the maintenance of equilibrium within the social environment (Schneider 1974). Interaction took place through reciprocity, redistribution, and exchange. Sahlins' (1965) further elaborated on reciprocity based exchange by placing generalized, balanced, and negative reciprocities along a continuum that served to describe the dynamics of interaction within specific social contexts. Another distinction lay between the transfer of inalienable gifts between reciprocally dependent individuals "that establishes a qualitative relationship between the transactors" (Gregory 1982: 101) and alienable commodities as transfer between reciprocally independent people "that establishes a quantitative relationship between the objects exchanged" (Gregory 1982: 100).

A number of critiques have emerged of the substantivist approach. One critique of substantivist approaches to exchange, one that is true of functionalism more generally, is an early version of agency theory. In the substantivist view, society is constructed of consistent rules within agents must act and includes a moral obligation of exchange (Dalton 1969: 77). In this organic perspective, however, "[t]here is little room for individual construction of social strategies and manipulation of rules, and there is little intimation of conflicts and contradictions between interests" (Hodder 1982: 200).

A second critique focuses on the distinction drawn by substantivists between complex and small-scale societies. Among complex societies, formal approaches are supposed to be more relevant, but in the context of small-scale societies substantive approaches are appropriate, and this dichotomy creates a dilemma of where exactly to draw the line. Monica L. Smith (1999: 111) argues that the ethnographic cases to which many substantivist models refer (i.e., small-scale societies) are lower in population density and involve fewer layers of interaction than would have been found in premodern states and empires and therefore formal approaches might have more relevance in premodern complex societies than is presented by substantivists.

A third critique holds that the direct correlation between forms of exchange and level of socio-political complexity lacks empirical support (Hodder 1982: 201). Anthropological studies suggest that unpredictability in food supply correlates with more extensive reciprocal exchange systems. Reciprocity is encountered more frequently among hunters, fishers and farmers than among gatherers and pastoralists who exploit relatively predictable resources (Pryor 1977: 4).

In the current day, Polyani's framework centering on the distinction between reciprocity, redistribution and market forces continues to be widely used in anthropology and archaeology, despite the development of alternative models that are particularly relevant to studies of commercialized pre-modern states. In particular, Michael E. Smith (2004) argues that more refined differentiation of transaction mechanisms can be used to distinguish the degree of internal and external commercialization in state-level societies, such as those presented by Carol A. Smith (1976). However, the subtleties of ancient commercial enterprise are less relevant in places like ancient Egypt and the Andes where historical and archaeological evidence attest to strong state control of uncommericalized economies without market-based economics, money, and independent merchants. In other words, Polyani's coarser distinctions of reciprocity, redistribution combined with non-market trade are sufficient in regions such as the ancient Andes where most scholars believe commerce played an minor role in prehistoric development (LaLone 1982;Stanish 2003). In Mesoamerica, however, where evidence for prehispanic markets and traders is widespread, anthropologists have found that Polyani's distinctions are vague and that models with further refinement in modes of commercialization are applicable (Braswell 2002;Smith 1976;Smith 2004).

Complementary applications of formal and substantive approaches

Formal and substantive approaches can be applied in a complementary manner. For example, in Stone Age Economics, Sahlins (1972) attempts to explain the existence of supply and demand curves among aboriginal exchange networks where social parameters determine the development of exchange. Winterhalder (1997) discusses some of the concepts presented by Sahlins (1972) using a behavioral ecology approach to gifts and exchange among non-market foragers. Winterhalder finds that issues such as social distance can be addressed more explicitly in a formal framework, albeit more narrowly, because economizing, neoclassical assumptions are a starting point for this type of analysis. As Hodder (1982: 200) points out, formal and substantive approaches are targeting different behaviors; formal economics relies on outputs and performance, while substantive analyses relate to social contexts of exchange.

While these differences make the two approaches irreconcilable on some levels, some studies attempt to integrate both avenues of research. Drawing on the advantages of both formalism and substantivism may be worthwhile, but a tendency to apply formal analyses to state-level societies, due to greater commercialism and specialization, and to apply substantive analyses to small-scale societies, should be resisted (Granovetter 1985;Gregory 1982;Smith 1999). The assumption that in premarket social contexts economic behavior is heavily embedded in social relations, but then is increasingly atomized and conforming to neoclassic analyses in modern, market-oriented societies is inconsistent. Granovetter (1985: 482) writes

I assert that the level of embeddedness of economic behavior is lower in nonmarket societies than is claimed by substantivists and development theorists, and it has changed less with 'modernization' than they believe; but I argue also that this level has always been and continues to be more substantial than is allowed for by formalists and economists (Granovetter 1985: 482).

Similarly, Danby (2002) observes that there are serious logical flaws in the false dichotomy, widely applied by archaeologists, where neoclassic, cost-minimizing logic is applied to premodern, complex societies but increasingly assuming an embedded "gift" economy among smaller-scale economies.

This dissertation research project follows on the substantivist tradition in the Andes, but formal approaches have been influential in exchange studies worldwide. The weaker elements of the substantivist approach will be avoided by not assuming a direct correspondence between socio-political complexity and volume or type of exchange.

Exchange and social distance

The dominant ethnographic approach in twentieth-century substantivist anthropology contrasts non-western gifting and exchange with capitalist, market-oriented trade in alienable commodities. Malinowski (1922) describes forms of exchange ranging from pure gifts to trade with increasing self-interest and "equivalence" as one moves towards the trade relationship. Mauss (1990 [1925]) attacks the notion of the pure gift and instead focuses on the temporal aspects of gift-giving, with the establishment of what are effectively ancient forms of credit. Further, Mauss focuses on the sociality of gift exchange with the idea that gifting can take hostile forms by inflicting obligations that the recipient may fear. Sahlins (1972: 191) subsumes the sociality of exchange relationships into a single trajectory with the concept of social distance. The "social distance" between exchange partners is a way of conceiving of the degree of familiarity and information transfer between producer and consumer of goods.

In Sahlins' classic taxonomy of reciprocity he identifies generalized, balanced, and negative reciprocity as a continuum from gift through exchange to haggling and theft, with explicitly different moral standards applying to transfers occurring in each sector. These modes of reciprocity were mapped directly on to increasing social distance originating in the household, although Sahlins was unspecific about the institutional forms of exchange, allowing for wide cross-cultural variation.

Besides the functionalist underpinnings of Sahlins' approach, one critique of his social distance model rests on his distinction between the role of the state and social relationships based on economic ties.

Because Sahlins is constructing a general theory, he is not obligated to deal with the refractory ethnographic data of one particular group. Hence, Malinowski's multiple heterogeneous categories of gifting never arise. In its place, Sahlins has a single Big Idea developed in the famous chapter on Hobbes and Mauss. The idea is that economics is politics for primitives. The understructure of human society, the default, is the chronic insecurity of Hobbes' "war of all against all." Primitives lack the state that is Hobbes' preferred remedy (Danby 2002: 24).

The result for Sahlins rests on a weak dichotomy between primitive|modern economic contexts that includes (1) primitive contexts where relations are mediated by social and economic relationships, and (2) modern contexts given over to the logic of neoclassic economics because commercialization and the circulation of alienable commodities are qualitatively different. Danby presents instead a "post-colonial critique [that] sees gift|exchange as yet another mapping of primitive|modern, an ultimately tautologous them|us split in which 'they' are various negations of what 'we' think 'we' are" (Danby 2002: 32). Anthropologists have sometimes followed this dichotomy where long-term investment and the establishment of social relationships in transactions is given over to the gift side, while exchange in alienable commodities is expected in complex, state level economies where exchange transactions are analyzed following the neoclassical approach and spot transactions are conducted in open markets.

In contrast, Danby argues that, if anything, one should expect greater temporal complexity and mechanisms for extending forward credit with greater social complexity.

Rather than building theory by pushing off against neoclassical exchange, let us put neoclassical exchange aside... the asocial spot transactions on the right-hand ends of [Sahlins' (Figure 2-1)] gift-exchange continua are also marginal to wealthy capitalist economies. Forward, debt creating transactions, embedded in social relations that often entail power, are central. Moreover, they are likely to be socially embedded in a variety of ways that should lead us to rethink the dichotomies between non-gift and gift (Danby 2002: 28).

Instead of framing the anthropological discussion of exchange in opposition to neoclassical approaches, Danby argues that the discussion should be reframed around institutions that underlie transactions in society and provide the long-term temporal milieu within which transactions occur. Temporality is particularly important when exchange is framed by production calendars based in agricultural cycles and by social calendars centered on gatherings and ceremonial occasions. By this standard, goods lying on the inalienable end of the continuum are fundamental to examining all economies in an anthropological light.

Common goods and luxury goods

The inalienability or uniqueness of an object sometimes parallels the categories of common and luxury items, with common items being mutable and replaceable. Yet, the classification as 'common' or 'luxury' for a given object is not discrete. It has been widely observed that the distinction between common and luxury items is contingent in space and time.

The line between luxury and everyday commodities is not only a historically shifting one, but even at any given point in time what looks like a homogeneous, bulk item of extremely limited semantic range can become very different in the course of distribution and consumption...Demand is thus neither a mechanical response to the structure and level of production nor a bottomless natural appetite. It is a complex social mechanism that mediates between short- and long-term patterns of commodity circulation (Appadurai 1986: 40-41).

Appadurai presents sugar as an example of a product with widely varying significance, and he observes that it is not merely the possession of exotic goods, but also the social significance of the knowledge surrounding the production or consumption of these goods, that carries significance. Goods that are irregularly distributed in space, portable, and that have wide consumption appeal such as sugar, salt and obsidian, were transported great distances in prehistory. For example, in the Mantaro Valley of the central Andes, Bruce Owen (2001: 280) notes that a number of metal items such as copper needles went from being wealth goods found primarily in elite contexts prior to the Inka conquest, to being utilitarian items and found with equal frequency in commoner contexts under Inka rule.

The movement of commodities has the significant effect of reinforcing relationships between social groups in the sense that the Kula ring promotes regular contact (Malinowski 1984 [1922]). However, in circumstances where the elite strive to control consumption of commodities, exchange can threaten the position of the elite. In Appadurai's perspective, both rulers and traders are the critical agents in articulating supply and demand of commodities.

The politics of demand frequently lies at the root of the tension between merchants and political elites; whereas merchants tend to be the social representatives of unfettered equivalence, new commodities, and strange tastes, political elites tend to be the custodians of restricted exchange, fixed commodity systems, and established tastes and sumptuary customs. This antagonism between "foreign" goods and local sumptuary (and therefore political) structures is probably the fundamental reason for the often remarked tendency of primitive societies to restrict trade to a limited set of commodities and to dealings with strangers rather than with kinsmen or friends. The notion that trade violates the spirit of the gift may in complex societies be only a vaguely related by-product of this more fundamental antagonism (Appadurai 1986: 33).

The suggestion that exchange promotes contact that threatens elite control results from either a relatively independent group of traders, or competing elites that utilize external contacts to advance their positions. Appadurai's point, however, is that in the realm of political finance one might expect established elites to strive to exert greater control over the values of production and exchange rather than relegate this important issue to those who traffic in long-distance goods, such as caravan drivers.

Following Polanyi, one might expect to find that in complex, premodern societies without market-based exchange there was dominance of administered trade. However, a number of scholars have observed that Polanyi (1957) appears to have ruled out precapitalist commercialism in ancient states a priori, as he claimed that there were no true markets or prices that reflected supply and demand in the ancient world, but rather equivalences in value that were set by rulers in an administered context. These "dogmatic misconceptions" (Trigger 2003: 59) appear to have caused Polanyi to distort the historical evidence as his views of administered markets in premodern states have been widely refuted (Smith 2004: 75-76;Snell 1997). Historian Philip Curtin (1984: 58) observes that even within contexts of administered control traders may have had more freedom than previously thought.

In some regional contexts, such as the prehispanic Andes, Polanyi's interaction types continue to be viable because there is little evidence of commercialization and open markets. The prevailing interpretation of prehispanic economy, for the Inka period in the central Andes at least, is "supply on command" (LaLone 1982) with elite economic domination primarily through labor mobilization. This issue will be explored in more detail in the Chapter 3, but Andeanists have largely found that Polanyi's non-commercial typology of premodern exchange suffices for analyses of prehispanic Andean economies.

Exchange promotes interaction between communities, yet Appadurai also explains that "such a tendency is always balanced by a countertendency, in all societies, to restrict, control, and channel exchange" (1986: 38). Under the rubric of "politics of value" Appadurai describes a pattern of institutional or elite control of commerce monopolizing or redirecting the flow of commodities. On this issue Graeber characterizes Appadurai's 1986 framework as "neoliberal" and describes it as follows

Appadurai leaves one with an image of commerce (self-interested, acquisitive calculation) as a universal human urge, almost a libidinal, democratic force, always trying to subvert the powers of the state, aristocratic hierarchies, or cultural elites whose role always seems to be to try to inhibit, channel, or control it. It all rather makes one wish one still had Karl Polanyi (1944) around to remind us how much state power has created the very terms of what is now considered normal commercial life (Graeber 2001: 33).

Appadurai cites examples of historic royal monopolies and sumptuary laws restricting trade items in Rhodesia and renaissance Europe support his argument (Appadurai 1986: 38). However, without the state-organized overhead of basic institutions guaranteeing peace, investment, and the protection of property, the movement of goods would involve much more danger of theft by brigands or goods could be simply confiscated by rival authorities.

Appadurai's focus on consumption is a significant contribution in that it releases anthropologists to address activities specifically related to consumption behavior, even though the neglect of production presents an incomplete picture of economy. Consumption loci are often the contexts where the strongest evidence or patterning of interaction is found. Thus, consumption is particularly useful to archaeologists who may only have evidence of changing consumption patterns, or who must infer links between production and consumption indirectly.

Exchange in subsistence, cultural, and prestige technologies

The distinction between the circulation of common and luxury goods observed by anthropologists can be considered in terms of the larger economy and the organization of technology by linking these concepts to those of practical and prestige technologies. As described broadly by Hayden (1998), practical technologies are those that are primarily organized around principles of sufficiency and effectiveness, while the logic of prestige technologies is fundamentally different because it is oriented towards social strategies where greater labor investment in products serves to communicate the wealth, success, and power of the parties involved. A third category, termed cultural goods, will also be used to examine the relationship between material culture and exchange. The concepts of practical, cultural, and prestige goods will be used to link long term changes in the organization of technology and production with consumption patterns and socio-political evolution.

This framework is relevant to this discussion of anthropological approaches to exchange because it places the contrasting behavior that Appadurai terms "common" and "luxury" goods into an empirical and evolutionary framework capable of addressing change over long time periods. Thus while the earlier discussion of "luxury goods" that transcend social and political boundaries referred to particular contexts of circulation, these are specific manifestations of goods Hayden would include in the broad category of prestige technology, as these objects are labor intensive to produce or acquire.

The concepts of practical and prestige technologies parallel in some ways the economic distinction made by Earle (1987;1994) between subsistence and political economies. The household level subsistence economy is based on satisficing logic, while the political economy involves the mobilization of surpluses and competition between political actors, and is subject to the maximizing strategies of elites. The organization of technology is sometimes approached in terms of three groups as Binford (1962) has done with "technomic", "sociotechnic", and "ideotechnic" categories. For Binford, technomic objects correspond to "practical technology", and the sociotechnic and ideotechnic groups would largely, but not exclusively, overlap with "prestige technologies". Hayden (1998: 15) observes that labor inputs are low but sociotechnic significance is high in Australian Aboriginal string headbands that signal adult status, and labor is low but ideotechnic significance is high in a pair of crossed sticks tied together to represent a crucifix. Hayden points out that despite these exceptions, items of ritual and social significance are often made with relatively costly materials (such as gold crucifixes) but he admits that many items fall between his categories such as decorated antler digging-stick handles, and "the analysis of such objects becomes especially complex where the prestige materials such as metals or jade are actually more effective, but far more costly, than more commonly used materials" (Hayden 1998: 44-45). Obsidian presents a similar dilemma where, on the one hand it is rare in many regions, and it is unusual-looking, and yet it is also more effective for many kinds of cutting functions and so the inducement to use the material is not straight-forward. As an object can move between categories it should be said that ultimately the significance of an item is not an inherent property of the object, but rather it is created by contexts of use or consumption and should best be considered in terms of labor, exchangeability or life-history (Appadurai 1986;Graeber 2001).

Table 2-1. Three categories of exchange goods, the boundaries on these categories are contingent on contexts of production, circulation, and consumption. Many items like meat, maize, and obsidian tools can belong in any one of these groups depending on form and availability.

According to Hayden (1998: 44) any material that is transported more than two days should probably be considered a prestige technology due to labor investment, however he mentions that perhaps a useful intermediate category of "cultural goods" could be defined consisting of non-prestige ritual or social artifacts. In his analysis of long distance caravans in the Andes, Nielsen (2000: 66-67) borrows concepts from Hayden's practical and prestige technologies with some modification for a discussion of exchange goods. Nielsen defines "subsistence goods" and "prestige goods", but he also defines a third category as "cultural goods" to include maize used for subsistence but also for ritual, as well as coca and textiles. These goods are often non-exclusive, but their form and consumption carries significance and the circulation of such items does not conform to the satisficing logic of practical technologies and subsistence goods.

Ordinary goods and archaeological theory

The fact that many artifacts cannot easily be classified into one of the above groups in a particular time or cultural context shows the difficulties inherent in developing a generalized framework for addressing production and exchange through prehistory. Obsidian is a prime example of a material that has practical value, but it is visually distinct and it is also a material with cultural significance and prestige associations in some contexts. Thus, while the focus in exchange studies has been on prestige goods linked to status competition, because these activities have evolutionary consequences, subsistence goods may also contain social or cultural information. The association of items luxury or commonplace categories is a function of geography, technology, and socially defined valuation.

Exchange as a prime mover?

Regional exchange is of particular utility to anthropological archaeology because it is a material phenomenon that occurs at the intersection of social relationships, resource procurement, and individual or community differentiation. However, exchange has been attributed with great causal significance in the past and, while it provides evidence of particular utility to anthropologists and archaeologists, it is important to not ascribe excessive significance to exchange in human affairs. For example, to V. Gordon Childe (1936) long distance trade was a prime mover that had direct social evolutionary consequences. Engaging in trade had derived benefits that can affect the balance of power between competing polities and stimulate larger forms of organization.

In the 1970s, Rathje (1971;1972) proposed that it was the lowland Maya need for "essentials" like obsidian, salt, and grinding stones that propelled them to seek external sources for these scarce goods, initiating long-distance relationships. Those who control access to scarce materials accrued benefits from their position in the trade network, he argued, and hierarchies emerged from the differential access to these required, or desired, trade goods. Virtually all of Rathje's postulates have since been disproved, but some variant of the theme first articulated in Rathje's exchange model underlies many contemporary investigations of ancient trade (Clark 2003: 33-34).

In the multilinear evolutionary framework of Johnson and Earle (1987), trade is part of an array of processes that are relevant to socio-political development, but trade does not become a dominant process until the formation of the Nation-State.

Table 2-2. Economic processes in political evolution (Johnson and Earle 1987: 304) where capitalized words indicates a dominance of that process, parenthesis indicate important secondary processes.

The approach taken here is that all human groups engage in exchange in some form and it therefore serves as a consistent index of regional relationships through time. Furthermore some trade items, such as obsidian, appear to have been part of a suite of features that, at particular times and socio-political contexts, serve to differentiate individuals or groups from the rest of their community for purposes relating to political strategy. While exchange is not a prime mover for socio-political change, transfer between peoples and groups in different forms provides a vehicle for social differentiation and a materialization of geographical relationships that are closely linked to socio-political organization. Thus, while one may see exchange occurring over the long term, it is not a prime-mover but it is changes in evidence of production, transfer, and consumption of non-local goods that inform theoretical models of prehistoric change.

Exchange concepts reflect the current theory

Forty years ago, advances in technical analysis in archaeology, in particular geochemical sourcing, initiated several decades of research into exchange by archaeologists. Following the dominant theoretical approaches of the time, adaptationalist or managerial models held that socio-political change was stimulated by factors that impacted the entire cultural system. Such changes could be stimulated by a combination of factors, including external pressures and internal pressures. External pressures include resource stress, drought, and warfare. Internal pressures include greater efficiency in organization despite larger population levels, irrigation, and organizational complexity due to circumscription.

More recent theoretical approaches focus on social and political strategies prioritize the active role of individuals in the process of political change. The role of commodity exchange in the onset and dynamics of socio-political complexity connects the exchange behavior documented by anthropologists with the long term changes that underlie the archaeological evidence of exchange in prehistory. Leveling mechanisms among hunter-gatherers promote intergroup sharing and are especially prominent when resource predictability is low. With greater resource predictability, and especially when resources are intensifiable, these leveling mechanisms often begin to break down and social differentiation is observed.

Exchange is thought to have been one of a number of interacting behaviors by "aggrandizing" individuals that had the indirect result of institutionalizing social inequality (Clark and Blake 1994;Flannery 1972;Hayden 1995;Hayden 1998;Upham 1990). What were the socio-political contexts that permitted individuals to differentiate themselves, and how did individuals pursuing their interests result in the long-term changes observed archaeologically?

Early leaders

While early social hierarchy emerged from the so-called egalitarian contexts of small-scale societies, Wiessner (2002: 233) observes that "hierarchy characterizes the societies of our closest non-human primate ancestors and seems to be deeply rooted in human behavior" and social hierarchy can therefore be considered a "reemergence" of hierarchy. Egalitarianism is not the "tabula rasa for human affairs on which aggrandizers impress their designs" (Wiessner 2002: 234); rather, it is the result of coalitions and complex institutions of weaker individuals in society that curbs the ambitions of the strong and results in egalitarian structures that were as complex and varied as hierarchical power structures. Wiessner argues that cooperative behavior, such as elaborate exchange relationships, in egalitarian institutions fostered ideologies of coalition building and cooperation in kinship-based networks that extended far beyond local groups. While the egalitarian ethos constrained the competitive activities of aggrandizers, these institutions also provided powerful tools to the cooperative structure that could be used to the advantage of aggrandizers. Exchange has particular significance in agency models that strive to explain how the activities of aggrandizers can result in institutionalized inequalities because exchange can contribute to an understanding of the relationship between structure and agency at this juncture.

Aggrandizers had to work within powerful institutional boundaries that already existed in egalitarian societies in order to forward their interests. The changing nature of exchange, embedded within shifting institutional contexts, complements the emphasis on alienable commodities (Appadurai 1986, see Section 2.2.2). Aggrandizing individuals operate within institutional contexts, indeed their vehicle to promotion is social recognition, yet the ability to organize resources to obtain lower costs for particular items benefits aggrandizers and their supporters. Exchange is a universal feature of human societies, and studies that document the diversity of forms that exchange takes in contexts of early social ranking can shed light on the specific strategies used by aggrandizers that resulted in institutionalized inequality (Clark and Blake 1994).

Prehistoric institutions

Beginning with settlement pattern studies explored by Julian Steward, processual archaeologists often assume regional perspectives that emphasized social and organizational processes (Willey and Sabloff 1974). Building on Polanyi's observation that fundamental aspects of human institutions are economic, archaeologists understood that documenting the regional distributions of artifacts resulting from prehistoric mobility or exchange could contribute to reconstructing past societies. Archaeologists can use direct evidence from the production and consumption of archaeological materials and inference about the likelihood and form of prehistoric exchange to point to the institutional contexts of the ancient economy.

In Polanyi's (1957) seminal article outlining the substantive approach, "The economy as an instituted process," the economy is characterized in terms of two linked properties. First, there is the material process by which items are produced, circulated, and consumed; second, there is the economic form organized around socio-political relationships that arranges interactions diachronically and spatially. In this context, institutions serve as rules and obligations connecting human organizations around the process of producing and circulating goods. The implication is that an archaeological study of variation in prehistoric economies requires that archaeologists can document differences in the institutions that structured past economies.

Many contemporary theoretical approaches downplay the importance of structural analyses in favor of agent-based models, however anthropologists using New Institutional Economics (North 1990) are emphasizing the interdependence of institutions and economics and the implications for activities of individuals (Acheson 2002;Ensminger 2002). Douglass North (1990: 3) defines institutions as "the rules of the game in a society or, more formally, the humanly devised constraints that shape human interaction". This view considers how institutions developed from the decisions of individuals over long periods of time, affecting transaction costs through the benefits of coordinated activity. "Based on the advantages of lower transaction costs in commodity flows, [these anthropologists] argue that political and social institutions developed to regulate commodity flows, maintain regional peace, and guarantee contracts" (Earle 2002: 82). In this perspective, institutional complexity developed as rules to govern the economizing nature of individuals, and the emergence of such institutions should be correlated with increasing quantities of commodity exchange in prehistory. The perspective that argues that volume of exchange should correlate with increased social complexity has roots in theories of progressive evolution (Childe 1936), adaptionalist views (Steward 1955), and the managerial role of chiefs (Service 1962).

However, a positive correlation between evolving institutional complexity and a uniform increase in volume or variety of exchange in prehistory is not supported empirically (Brumfiel 1980;Hughes 1994;Kirch 1991). That is, contrary to the evolutionary expectations of some theorists, the volume or variety of goods transferred does not necessarily reflect the political or institutional complexity in a given society. Perhaps some of this inconsistency is the result of elite control of the circulation of commodities as proposed by Appadurai (1986: 38). Earle (1994: 420-421) observes that on the whole, the archaeological evidence is characterized by a great deal of variability in the types of goods exchanged, the volume of exchange, and the social contexts of exchange. In order to address this variability in an evolutionary framework, Earle suggests that exchange should be considered in terms of two categories, the subsistence economy and the political economy[1](Johnson and Earle 2000), with exchange taking different forms in each category of the economy. The exchange in these two forms of economy correspond largely to the distinction discussed earlier between ordinary goods and prestige goods where, according to Earle, political strategy is advanced by elites by, among other things, the manipulation of exchange relationships.

In a non-evolutionist application of New Institutional Economics in anthropology, Wiessner (2002: 235) differs from North in arguing that transaction costs for exchange are actually high in small-scale societies due to the close relationship between social and economic transactions; there is less neutral space for "unembedded" economic behavior with their associated overhead costs. In such contexts egalitarian institutions developed to foster trust and make interactions more predictable.

In non-market economies in which kin-based exchange systems play an important role in reducing risk (Wiessner 1982;Wiessner 1996) the goal of exchange is to be covered in times of need. In this context, the social and the economic are closely intertwined (Mauss 1925) and it is undesirable for returns to be stipulated as to time, quantity, or quality (Sahlins 1972). The most valuable information in such exchanges is the details of the partner - what he or she has to offer and will offer over the long run (Wiessner 2002: 235).

Elaborate institutions regulating behavior are not new, argues Wiessner, but if there is a weakening in the egalitarian prohibition against the accumulation of wealth or power the "alchemy of ambition" (Wiessner 2002: 234) drives a few individuals to seek preferential access to resources. In contexts of regional packing and circumscription it is argued that hierarchies emerge (Brown 1985;Johnson 1982) that are perhaps founded on the control of labor and surpluses, and instituted through ritual (Aldenderfer 1993;Hayden 1995)

Materialist perspectives hold that economic gains are used to bring about changes in the social order, and that these changes are then legitimized and perpetuated through ideology. These economic gains are generally achieved through intensification of production and through finance organized by ambitious individuals (Boone 1992;Earle 1997;Hayden 1995). Clark and Blake (1994: 17), building on practice theory (Bourdieu 1977;Giddens 1979), describe a model whereby institutionalized inequality is the unintended outcome of political actors competing for prestige by using strategies that match the self-interests of their supporters. Ultimately, these strategies may develop into redistributive institutions that appear to build on the social-leveling mechanisms described by Wiessner (1996), but operate on a larger scale and result in political advantage for redistributing leaders and their allies. In other words, it is institutions themselves that form the basis for leveling mechanisms, and it is institutions that are transformed into vehicles that serve to, in part, legitimize social inequalities.

An important temporal component to exchange is connected to institutions as well because transactions involve anticipation and scheduling. As Colin Danby (2002) argues, most transactions in neoclassical economic analyses in anthropology are considered as synchronic "spot transactions" of commodities, while long term interpersonal relationships enter the domain of gifts in a gifts: commodities dichotomy. The temporality of reciprocation is a means by which economic transactions are embedded inside of social calendars, but various socially-mediated methods of extending credit are well-established and probably an ancient manner of precipitating exchange in market-based transfers as well.

Pastoralism, caravans, and social inequalities

The domestication of cargo-bearing animals contributed several important elements that transformed the nature of regional exchange relationships. First, there are some cross-cultural commonalities in the structure of contemporary societies practicing pastoralism, and it is probable that these factors had some role in prehistoric pastoral societies as well. Second, cargo-bearing animals transform the costs of transport and, consequently, the nature of long-distance interaction. Finally, the structure of wealth in animal herds conveys particular scalar advantages to powerful kin-groups that possess large herds. These factors condition long-term transformations such as sedentism, the nature of food production, and the institutionalization of social inequalities. These issues will be explored in three sections: household level articulation with agriculturalists, wealth accumulation among herders that is limited by risk and pasture, and caravans and the organization of pastoral labor.

Polanyi and the economics of exchange

The principal forms of economic organization outlined by Karl Polanyi (1957) - reciprocity, redistribution, and market forces - have been widely used in anthropological discussions of exchange. Paul Bohannan describes the relevance of these economic modes to exchange:

Reciprocity involves exchange of goods between people who are bound in non-market, non-hierarchical relationships to one another. The exchange does not create the relationship, but rather is part of the behavior that gives it context.

Redistribution is defined by Polanyi as a systematic movement of goods towards an administrative center and their reallotment by the authorities at the center.

Market Exchange is the exchange of goods at prices determined by the law of supply and demand. Its essence is free and casual contract (Bohannan 1965: 232).

In principle, the price-fixing aspect of market based exchange has an integrative effect and entails communication between segments of the exchange sphere. For the trader, market exchange involves risk and potential profit. For the producer, the consumption patterns and fluctuations in demand should be sensed all the way back in the contexts of production. Market articulation in land-locked regions of Asia and North Africa provided the initial contexts for large-scale caravans in the Old World. With caravans perennially under threat of robbery or obligation to pay duties for crossing sovereign land, the "nomadic empires of the Turk, Mongol, Arabic, and Berber peoples were spread out like nets alongside transcontinental caravan routes" (Polanyi 1975: 146-149). In contrast to market mechanisms, Polanyi also described exchange modes of institutional or administered trade, where material needs were satisfied through the movement of goods but the practice was not motivated by "profit" for merchants in the market sense of the term but rather to meet institutional goals (Salomon 1985: 516;Stanish 1992: 14;Valensi 1981: 5-6). In this type of trade, value and equivalencies are established by political authority or by precedent.

Characteristics of a market economy

Markets are of particular interest in this discussion because while market principles, to a certain extent, underlie all formal economic approaches in anthropology, market-based economies are far from universal in the premodern world, even among state-level societies. A basic definition of a market is "the situation or context in which a supply crowd (sellers) and a demand crowd (buyers) meet to exchange goods and services" and where the market principle is operating (Dalton 1961: 1-2). Three characteristics used by Earle to evaluate the evidence for market-based exchange in the Inka state include: (1) The importance of specialized institutions of production and exchange divorced in their operations from other institutional relationships; (2) The development of a medium of exchange to facilitate the systematization of exchange values; (3) The percentage of goods utilized by a household that are obtained by exchange (Earle 1985: 372-373).

The presence of exchange institutions, either as bustling marketplaces or distributed as "site-free" exchange houses, have a characteristic described by Earle (1985: 373) as a context where "non-exchange relationships, such as kinship and political ties, will not unduly constrain choice". The alienability of products, the strong influence of price motive and the detachment from production and other social linkages, underlie many of the features of these proposed institutions. The consensus among Andeanists is that during Inka domination, and probably during the preceding periods, market-based economies were not found in the central and southern Andes with a few exceptions (Earle 2001;LaLone 1982; but see href="/biblio/ref_2005">Salomon 1986;Stanish 2003).

The location of transfer becomes important with respect to price-fixing markets. In aggregations the public nature of the contact and the circulation of information is quite different from isolated exchanges. These issues are linked to the spatial and temporal configuration of exchange in market economies because just as periodic gatherings, central places, and rank-size geographic relationships serve to distribute goods in some settlement systems, these aggregations serve to distribution information about availability of products and changing prices to buyers and sellers (Smith 1976;Smith 1976). When exchange takes place in a private courtyard rather than a public marketplace then there is reduced risk of the neighbor overhearing the barter exchange value offered to another (Blanton 1998;Humphrey and Hugh-Jones 1992). Greater public visibility and monitoring in market contexts might be expected, and greater privacy, interpersonal negotiation, and temporal depth to exchange relationships in private barter exchange configurations.

Variations on Modes of Exchange

Some scholars have built on Polanyi's four original modes of exchange, others have developed entirely new schema (Smith 1976). Earle (1977: 213-216) argues that Polanyi's (1957: 250) definition of redistribution as "appropriational movements towards a center and out of it again..." is vague and Earle observes that this definition is so broad that it could to apply to economic systems ranging from central storage of goods in Babylonia to meat distribution in band-level hunters. Earle advocates separating leveling mechanisms from institutional mechanisms, where institutionalized redistribution involves wealth accumulation and political transmission between elites across broad regions in the mode of peer-polity interaction (Earle 1997).

Exchange network structures

Based on geographer Peter Haggett's (1966) work, network configurations can be used to describe the characteristics of interaction that resulted in the distribution and circulation of goods. In describing Andean caravan transport, Nielsen (2000: 73-74, 91) uses the following terms: (1) distance that goods are transported; (2) segmentary vs. continuous - in segmentary networks a given node is connected to a small number of other nodes, while continuous networks each node is connected to all other nodes; (3) convergent (focalized) vs. divergent (non-focalized) - in convergent networks the individuals participating in exchange, and the goods they transport, tend to concentrate in a small number of central places or exchange locales.

Reciprocal exchange relationships that take the form of down-the-line trade may be described as continuous networks when these mechanisms serve to move goods between ethnic groups and across regions. Centralized political control by elites and true market mechanisms might result in network convergence at central places (Smith 1976). To Nielsen's third set of terms, convergent (focalized), divergent (non-focalized), one may add diffusive to describe the pattern of a single type of item radiating from the center to the surrounding region as occurs with obsidian.

Figure 2-3. Network configurations.

These network configurations serve to draw attention to the limitations of using raw material distributions as a proxy for all exchange behaviors. Obsidian exchange is sometimes used by archaeologists as gauge of the volume, frequency, and structure of prehistoric exchange relationships. As noted by Clark (2003), raw materials from geological sources diffuse continuously from a single point to the region, presumably following trade routes, until the materials are found deposited at archaeological consumption sites. In contrast, much exchange between complementary groups, such as between agriculturalists and pastoralists, is non-focalized and often segmentary, as it links producers and consumers through a variety of localized articulation methods. The structural differences between diffusive exchange networks and regular, household-level interaction are well demonstrated in mountain regions with distinct ecological zonation, such as the Andes.

Archaeological inferences that do not differentiate the expectations of one network configuration from another are problematic. Often, diffusive configurations will have evidence of the transport of goods in the opposite direction, as one might expect in system where obsidian is acquired through reciprocity-based relationships. However, the pattern where goods are reciprocated to the source area is a configuration model to be tested rather than one that can be assumed.

Exchange across boundaries

Anthropological accounts relate that acquiring resources through trade with neighbors is sometimes a dangerous undertaking that is maybe not far removed from raiding and warfare. "There is a link, a continuity, between hostile relations and the provision of reciprocal prestations. Exchanges are peacefully resolved wars, and wars are the result of unsuccessful transactions" (Lévi-Strauss 1969: 67). Further, Sahlins (1972) observes that reciprocity in trade between unrelated exchange partners in contexts without overarching political control can be a very delicate affair because sometimes it is only the perception of fairness in the exchange that maintains peace.

When people meet who owe each other nothing yet presume to gain from each other something, peace of trade is the great uncertainty. In the absence of external guarantees, as of a Sovereign Power, peace must be otherwise secured: by extension of sociable relations to foreigners - thus, the trade-friendship or trade-kinship - and, most significantly, by the terms of the exchange itself (Sahlins 1972: 302, emphasis in the original).

Yet exchange and markets across boundary areas are common features in world history. Such exchange could consist of "border mechanisms" with trade-partnerships or fictive-kin ties that permit "interactions across tribal boundaries under conditions of peace and personal security" (Harding 1967: 165). Zones between social groups are particularly likely to have active trade and markets if there is some cultural or ecological variation between the groups, such that the products circulating in each zone complement one another (Hodder and Orton 1976: 76). The No-man's-land described as the "Intertribal sector" by Sahlins (1965;1972: 196-204) is a good locale for such exchange because complementary products are available for exchange, and because the morality of exchange in neutral geographical territories permits balanced or negative reciprocity between traders. In perception of value, as well as geography, these border zones can be conceived as overlapping social "spheres of interaction" as described by Barth, where "entrepreneurs will direct their activity preeminently towards those points in an economic system where the discrepancies of evaluation are greatest, and will attempt to construct bridging transactions which can exploit those discrepancies" (Barth 1967: 171). These discussions of the details and great the variability in entrepreneurial strategy anticipate the challenges of an agent-based approach to ancient trade (Adams 1974: 243;Hodder 1982).

Exchange and social distance

The question of the isolation of producers and traders from consumers also connects theories about exchange with the issue of the physical form of the exchange goods. Archaeologists investigating the role of stone artifacts in prehistoric economies observe that lithic manufacture is a subtractive technology as stone artifacts always get smaller with use and maintenance. The degree of reduction of stone material at a lithic source determines the kinds of forms that subsequent artifacts will take.

Jonathon Ericson (1984) applies Sahlins' concept of a continuum of social distance in exchange relationships, discussed above, to the directional, reductive nature of lithic production systems. He explores the idea that the degree of lithic reduction that may occur could be reduced when social distance increases because the producer would have less information about the consumer and the end forms that material will take (Ericson 1984: 6). For example, if the procurer does not know if the nodule will be formed into bifacial lancoleate knife or a triangular projectile point by the consumer, it would be better to leave the nodule in a larger form.

Exchange partners can be slow to respond to changes in the needs of consumers in a given exchange system (Ericson 1984: 6;Harding 1967;Rappaport 1967;Spence 1982), and the effects of social distance can impact production, exchange, or consumption patterns. The implications of social distance for lithic reduction are that, as a subtractive process, reduction circumscribes the potential artifact forms that a nodule of raw material may take in the future. Countering this tendency, people can reduce risk in tool production by producing blanks closer to the source of a raw material where the value of a material is lessened and the costliness of knapping error or breakage, and inconsistent or poor-quality material, is reduced. Stylistically, producers may wish to impart a local motif to the material; alternately, in order to maximize distributive potential, a good may be left in a minimally reduced form.

The exotic and value creation

Non-local exchange goods are prominent in anthropological models of socio-political change because exchange goods can accrue value directly as a function of scarcity, labor input, or through social and symbolic reference. As discussed above under the subject of practical goods and prestige goods, a given object may move between practical and prestige categories in different places, times, and social contexts. The availability of an item in a given milieu communicates not only the relative scarcity but, for alienable goods, the exchange value of that item; such items may also contain allusions to distant regions, social groups, and esoteric knowledge.

Theoretical models assert that in order for sacredness or exotic power to be conferred through possession of non-local goods, those goods cannot be widely available or mutable in economic circles accessible to just anyone (Clark and Blake 1994;Goldstein 2000). The possession and circulation of these goods have also been considered as part of a network strategy, distinct from a corporate strategy, towards acquiring influence and leadership (Blanton, et al. 1996). These goods may have served as indicators of long-distance association for trade and alliance, and also have served as a means of differentiation during this time of incipient political competition. In another approach, one that focuses on differential reproductive success, Craig and Aldenderfer (in press) use costly-signaling theory in a formal, biological adaptationist framework to model the development of social inequalities through the differential use of obsidian in southern Peru at the Archaic and Formative transition. Exotic materials have been used to demarcate commonplace from supernatural referents, or are at least part of a constellation of behavior and objects that signal status difference.

A pattern noted frequently by archaeologists is that close to the source of a raw material there is no distinction associated with the commodity as the item is abundant, whereas farther from the source, where access is intermittent, the possession of such commodities may acquire greater symbolic importance (Knapp 1990: 161;Renfrew 1986). It follows that if one moves from a place where a product is scarce and found in ritual contexts, towards the source of that product such that it becomes less scarce, one may observe a reduction in ritual or exclusive association for that group of goods. This theme will be considered with obsidian use in the Lake Titicaca region.

Furthermore, what of those who transport exotic goods? Mary Helms argues that "we should consider long-distance travelers or contact agents as political-religious specialists, and include them in the company of shamans, priests, and priestly chiefs and kings as political-ideological experts or 'heroes' who contact cosmically distant realms and obtain politically and ideologically useful materials therefrom" (1992: 159). These agents are in a position to benefit, in an entrepreneurial way from the value difference, between the source and the consumption zone, but in many cultural contexts their participation and social roles appear to be circumscribed. The association of non-local goods with status or prestige, long-distance alliance or esoteric knowledge is contingent on a variety of factors upon which it is difficult to generalize, but one can examine these archaeologically through artifact form and context.

California multiethnic access

One possible arrangement is multiethnic procurement at a geological source. Ericson (1982: 136) describes a situation in California's Napa Valley where the Saint Helena obsidian source fell within the territory of the Wappo ethnic group and the Wappo were, in turn, surrounded by the Lake Miwok, Coast Miwok, Wintun and Pomo groups (Kroeber 1925). It is reported that in exchange for obsidian, the Wappo received items such as bows, beads, shells, mats, fish, headbands, and clams (Davis 1961), but it is not known if extraction was conducted by the local Wappo or through direct access by the surrounding groups themselves. Ericson (1984: 7) reviews evidence of multiethnic access to lithic sources. In California there are a number of distinctive obsidian sources that have been studied. At some areas the quarry management was "tribal but related and nearby groups had the right to quarry either freely or on the payment of small gifts. Wars resulted from attempts by some distant tribes to use a quarry without payment. On the other hand, the Clear Lake obsidian quarries were neutral ground" (Bryan 1950: 34).

The Wintun of California practiced round-trip fasting when traveling to obsidian sources (Dubois 1935). A functional interpretation of this behavior from Ericson (1984: 7) is that fasting would avert exhaustion of resources around much-visited obsidian sources. A regionally important quarry could conceivably get so much use, with many groups exploiting the source, that the ecology of the source area catchment would get depleted.

Geochemical studies of obsidian artifacts in California have revealed a concordance between obsidian distributions, as shown by chemical studies, and the geographical boundaries of ethnographically documented cultural groups (Bettinger 1982;Hughes and Bettinger 1984;Luhnow 1997). Dillian (2002: 294-297) found that despite ethnographic accounts of Karok direct procurement at the Glass Mountain source in Modoc territory, the knapping evidence at the source suggests that local Modoc were conducting virtually all of the reduction on site and then exchanging with neighboring tribes where it was widely circulated.

Other Source Areas

The well-known red pipestone quarry in Minnesota "was held and owned in common, and as a neutral group" (Holmes 1919: 262). In the Western Desert of Australia, Gould et al. (1971) report that chert and chalcedony sources themselves are not held through a concept of quarry ownership. All material of usably good knapping quality is equally valued, and knapping is not a skill that is assigned great importance. However, an important totemic affiliation exists between a person and stone from the region in which they were born. Cherts from a person's ancestral region are sometimes visually distinct and therefore materials of a particular region will be sought and transported over long distances as a physical link to those regions.

These preferences appear to be a reflection of the close totemic ties each man has to the particular region in which he was born and from which he claims totemic descent. Thus, a man may have a sense of kinship with some of these localities, and he will value the stone material from them as a part of his own being. Stone materials thus acquired are not sacred in any strict sense but are nevertheless valued highly enough to be transported over long distances by owners (Gould, et al. 1971: 161-162).

Ideological and emotive links to raw material are a consideration in human activities around source areas. Social and symbolic restrictions on quarries have also been documented ethnographically in New Guinea (Burton 1984;McBryde 1984). In terms of exchange behaviors, quarry areas present special problems and opportunities for archaeologists. One of the principal difficulties with examining ethnicity and access to quarries is correlating archaeological evidence with social and symbolic behavior associated with quarries. Some theoretical models are contingent on measuring evidence of maximization and control of production at quarry areas, and these models are often contingent on the detection of boundaries and restricted access based on material evidence (Torrence 1986). Unfortunately, as demonstrated by some of the studies above, many social and symbolic limitations on quarry access leave no direct material correlates and can be extremely difficult to detect archaeologically.

Exchange value

Exchange from the perspective of commodity 'exchangeability' and demand by consumers is a cross-culturally comparable (and often archaeologically detectable) means of assessing value, but this approach depends on the goods actually circulating. Others have observed that some inalienable objects (heirlooms) are valued precisely because they do not circulate, and the ability of an object to "accumulate history" is another means of establishing value albeit a measure that is difficult to establish archaeologically.

Social distance

The continuum of social distance is useful in that it captures the role of different behavior and institutions in exchange as one moves away from the household, and it may parallel formal models of kin selection. Further, the concepts of production and social distance for a commodity like obsidian can be empirically linked to expectations about the degree of lithic reduction as one moves from production to consumption contexts. The use of the social distance concept to position a diachronic, "primitive" household (substantive) exchange against a synchronic, "modern" and commercialized (formal) realm is a problematic and false dichotomy. Virtually all exchange contexts contain elements of both social contracts and economical behavior. Social distance, territoriality, and access to products can be manifested in a variety of ways that range from the organization of technology, socially circumscribed access, and symbolic restrictions; a situation that poses difficulties for archaeologists attempting to establish the relative accessibility of a particular product prehistorically.

Social and political consequences of exchange

Exchange is a mechanism that brings goods and people together between ecological zones and across social boundaries, and exchange creates strategic opportunities for individuals and institutions. Exchange is sometimes used to reinforce status differences because the possession of exotic goods, and the necessary surplus to acquire non-local products, differentially favors those with established regional ties. However exchange across boundaries, along with warfare and ritual, can be dangerous and may be the domain of strategic and opportunistic individuals as traffic in the exotic, and contact with foreign elements, is liable to challenge the social order. Conversely, one of the often-noted social consequences of regular exchange is more mundane: exchange serves to reinforce long distance social ties over time, to buffer risk, and to express cohesiveness through common access to distinct resources.

In recent decades, exchange studies in archaeology have acquired new technical rigor with advances in chemical proveniencing. While the cultural, institutional, and theoretical ramifications of exchange remain complex and nuanced, the demonstrable fact of chemical characterization offers refreshing certainty to the otherwise conditional and qualified study of ancient exchange.

Measures of abundance

Investigators have compared changes in the abundance of non-local material with domestic goods that are assumed to represent population. The ratio of the weight of obsidian to volume of excavated dirt (as shown in Figure 2-5) or as a ratio of weight of ceramics (as a proxy measure for population) has been used in a number of studies in Mesoamerica (Sidrys 1976;Zeitlin and Heimbuch 1978: 189). In studies of Near Eastern obsidian exchange Renfrew (1969;1977) develops indices for the presence of obsidian based on counts and weights per phase and per excavated cubic meter, and he also uses the count of obsidian artifacts as a percent of the total lithic assemblage count. Renfrew qualifies his conclusions due to a lack of consistency in the data, but he estimates that the total quantity of to arrive at the site was relatively small and he observes a decrease in obsidian at Deh Luran sites. Working at the Olmec site of San Lorenzo Tenochtitlan, Cobean et al. (1971) develop an index that compared the number of obsidian flakes, blades, and total debitage with grinding stones and slabs for each phase at the site, with the abundance of grinding equipment serving as an estimate of number of households. The authors interpret the increasing index of obsidian to grinding slabs as evidence of a gradual rise in "prosperity" for individuals at the site, though they only briefly explore the implications for changing exchange relationships (Cobean, et al. 1991).

In Torrence's examination of the aforementioned studies she concludes that "the major difficulty with studies of consumption based on measures of resource abundance is that they lack the necessary linking arguments between patterns of consumption and type of exchange" (1986: 28-30). She states that what is needed for site-level studies of abundance and exchange is "a series of arguments describing how resource use will respond to specific types of exchange" akin to the explicit connections that Renfrew developed on the regional scale between distance decay and forms of exchange.

Site level composition from multiple sources

When raw material is available to consumers from several competing sources, investigators have used the relative quantity of materials from the different sources at individual sites to gain insights into ancient exchange. Broad exchange relationships are frequently inferred from the presence of obsidian from a distant source. When material from several rival obsidian sources are represented, either strongly or weakly, in different phases at a site, the cause of the changes in representation is often attributed to shifts in the geography of regional political or economic relationships. Geographical explanations are invoked when there is a clear deviation from the LMD, and yet evidence of significant in-situ political change is not found in investigations among studies in Mesoamerica (Zeitlin 1978: 202;Zeitlin 1982) and the Near East (Renfrew 1977: 308-309).

Changes in the mechanisms of exchange, rather than simply geography, are attributed to changes in the source composition from different sources when socio-political changes are perceived by investigators. Studies have inferred redistribution occurring when sites that act as central places (Christaller 1966 [1933]) at the top of the settlement hierarchy have disproportionate quantities of non-local materials irrespective of their distance from the source. This phenomenon has been discussed for Tikal (Moholy-Nagy 1976: 101-103;Sidrys 1977).

When sourcing studies are conducted at the scale of the household unit, though it is often labor intensive and costly to conduct proveniencing studies to an extent that are statistically meaningful, it is possible to discern convergence patterns that can be connected to exchange mechanisms (Pires-Ferreira and Flannery 1976;Santley 1984;Torrence 1986: 35). The most common application of evidence of variability between households in source composition is to infer redistribution from the presence of low inter-household variability in source composition.

In a reciprocal economy where individual households negotiate for their own obsidian, we would expect a good deal of variation between households, both in the sources used and the proportions of obsidian from various sources. Conversely, in an economy where the flow of obsidian is controlled by an elite or by important community leaders, who pool incoming obsidian for later distribution to their relatives, affines, or fellow villagers, we would expect less variation and more uniformity from one household to another (Winter and Pires-Ferreira 1976: 306).

The concept is been depicted in a graphic from.

Table 2-4. Household composition of raw materials should vary with different types of exchange. On the left, individual households acquire source materials more directly, on the right pooling and redistribution results in greater inter-household consistency in raw material composition (Winter and Pires-Ferreira 1976: 311).

This approach was influential in Mesoamerica (Clark and Lee 1984;Santley 1984;Spence 1981;Spence 1982;Spence 1984 ) where the technology of transport did not change significantly except for perceived changes in the form of boat technology. Transport changes could significantly impact the inter-household diversity of source composition in places, such as the Near East, where caravan exchange networks followed from the domestication of pack animals (Wright 1969). The impacts of caravan exchange on artifact variability has long been discussed in the Andes (Dillehay and Nuñez 1988;Nuñez and Dillehay 1995 [1979]), although household-level sourcing data has not been available to date.

Variation in site-level contexts and artifact form

Intrasite variability in lithic distributions, and the morphology of those artifacts, can shed light on exchange patterns. Several projects in Mesoamerica have inferred redistribution as the mechanism of exchange when concentrations of non-local lithic materials at major sites point to debris associated with specialist workshops and other kinds of intrasite use of space. Blade manufacturing debris has been used in this manner at Tikal (Moholy-Nagy 1975;Moholy-Nagy 1976;Moholy-Nagy 1991;Moholy-Nagy 1999), the Basin of Mexico (Sanders, et al. 1979), and Teotihuacan (Spence 1967;Spence 1984).

The proportion of artifact forms of a non-local material in a single site has been used to characterize mechanisms of exchange. This approach has proved useful with obsidian exchange in places where distinctive reduction strategies are associated with finished artifact form, such as blade technology, and these strategies can be recognized in lithic material found in consumption sites. Winter and Pires-Ferreira (1976: 309-310), working at two sites in Oaxaca, argued that blades of high quality, non-local obsidian were introduced to the sites in finished form and that this constituted evidence of elite pooling for prismatic blade reduction followed by redistribution to local sites. The higher quality material was transformed into more valuable artifact forms in workshops located outside of their study area, and then in the Oaxaca sites the presence of these artifacts that were apparently the result of contact with elite spheres of exchange, was interpreted as evidence of redistribution of the finished artifacts. The sourcing and exchange work of Pires-Ferreira has come under some criticism because in her initial proveniencing study she only used two diagnostic chemical elements, and more recent analyses suggest that many of her sourcing attributions are incorrect (Clark 2003: 32). Further, Sheets (1978: 62) argues that the edges of prismatic blades are too fragile to have been transported in completed form (Clark and Lee 1984: 272).

Systematic studies of the intrasite contexts and artifact form of non-local material have the potential to provide insights into exchange and social structure. Intrasite spatial patterns can be investigated in combination with both quantitative data stemming from geographical distances and artifact abundance, and with qualitative data inferred from artifact form and technological aspects of production (Torrence 1986: 36). These kinds of intrasite patterns are susceptible to distortion by dumping patterns and intrasite studies must be sensitive to the problems of conflating material from workshop refuse, household middens and construction fill (Moholy-Nagy 1997).

In a useful review of Mesoamerican obsidian studies Clark (2003: 32-39) summarizes major advances in provenience and trade models, and highlights important avenues for improvement. One important observation made by Clark is that in archaeologists' efforts to design systematic approaches to exchange, early studies failed to distinguish "power as energy and power as legitimacy" (Clark 2003: 38). It could be argued that these forms of power are largely comparable, as the ability to procure, display, and redistribute non-local goods demonstrates power in both energy and in prestige. However, as was emphasized by substantivists in their discussion on the inalienability of certain products, the value of particular status items rests precisely in their incommensurate nature.

Sanders and Santley's (1983) proposal that special goods were returned to Teotihuacan in exchange for obsidian products, and that these were cashed in for corn from the fringes of Teotihuacan's domain in hard times, fails to appreciate that once symbolic goods circulate like economic goods among the hoi polloi such goods lose any legitimizing powers (Clark 2003: 38).

A framework for investigating prehistoric exchange must negotiate between these features of the archaeological record. Material evidence of long-distance exchange is abundant and easily measured, but interpreting the significance and perceived value of these non-local products in the social and political context of their consumption is the measurement of greatest relevance to comprehending the role of exchange over time.

Background and methodological approach

Bradley and Edmonds (1993: 5-17) begin with a useful critique of the formal approaches to exchange first articulated in the work of Renfrew and his colleagues. In reviewing prior approaches, Bradley and Edmonds perceive weaknesses and untenable assumptions in the links asserted by prior researchers connecting (1) efficiency in reduction strategies, organization of production, and degree of hierarchy in social organization (Torrence, Ericson, others), and (2) geographical distributions of types of artifacts with the nature of social organization (Renfrew et al.).

Bradley and Edmonds emerge with a strategy that permits them to connect temporal change in quarrying and the organization of reduction in the immediate vicinity of the source with perceived changes in knapping strategies. They also explicitly attempt to incorporate evidence from social and symbolic constraints on quarries, where historical specifics about specialization, quarry access, and socio-political boundaries appear to trump the larger patterns of circulation documented during the 1970s by Renfrew, Hodder, and others (Bradley and Edmonds 1993: 9, 63). Further, the authors observe that while these social and symbolic control variables are extremely difficult to appraise from archaeological evidence, these unknowns were ultimately some of the most important variables informing Torrence's (1986) formal approach to efficiency and socio-economic control of production. On these grounds, Bradley and Edmonds devote more effort to methodological and theoretical goals that they feel are attainable: documenting variability in production, inferring connections with regional consumption evidence through temporal context, and exploring social and symbolic generalities through ethnographic analogy from quarries and with evidence of regional ground axe distributions in Britain.

Technical analysis

Bradley and Edmonds' (1993: 83-104) lithic analysis begins with experimental knapping studies that allow them to identify the character and frequency of different classes of flaked stone generated during production. Establishing reduction stages from flakes of Great Langdale tuff material is particularly difficult because the material does not contain a visible cortex. Bradley and Edmonds pursue strategies that produce a wide range of flake and core morphologies in an effort to capture the range of possible variation in reduction at production sites. Their expressed aims are to move beyond simple measures of efficiency in production, and they also seek to use their experimentally-derived assemblages to inform their analysis such that that they do not merely derive a single, generalized reduction sequence but, instead, shed light on how knappers controlled form, and anticipated and avoided mistakes.

It was just as important to discover which methods couldhave been used to make an artifact as it was to establish which were actually selected. It is clearly important to understand howthe production process was structured in a given context, but we also need to discover whyit took the form it did (Bradley and Edmonds 1993: 88, emphasis in original).

In earlier work Edmonds (1990) cites from, and applied, the chaîne opératoireapproach to his investigation of quarry production. Curiously, in the Bradley and Edmonds (1993) volume the French term does not appear (although they cite the chaîne opératoireliterature), and in their quarry production studies they instead choose terms like "pathways" to describe sequential reduction.

Part of Bradley and Edmonds' aim is to reintegrate symbolic and social perspectives into the study of quarry production and exchange, empirical archaeologists may ask: how do Bradley and Edmonds conduct symbolic and social analysis with lithic attribute data from a quarry workshop? In their data-oriented investigation of reduction strategies, Bradley and Edmonds gather standard lithic attribute data that is largely in common with those that follow the processualist tradition; it is in the interpretations and assumptions about economy that the differences emerge. For example, many of the assemblages are described by Bradley and Edmonds along a production gradient that range from "wasteful and inefficient" to "careful preparation" or ad-hoc versus structured production using evidence from flake dimensions, platform morphology and preparation, flake termination type, and other attributes.

For Bradley and Edmonds, efficiency is investigated primarily in a heuristic manner in association with spatial context in that they suggest expediency, investment, and reduction strategies over the larger quarry area. Their technical analysis is able to conclude, among other things, that axes appeared to be exported from the quarry area in two forms: (1) crude asymmetrical rough-outs with hinges and deep scars, and (2) more processed and nearly finished artifacts that lacked only polishing.

They also note that some processing appeared to occur at some distance from the quarry, and in other cases nearly all of the production sequence occurs at the quarry. The authors used evidence of excessive labor expenditure, such as in axe grinding and polishing, as a contrast to the "rational", cost-minimizing expectations of efficient production expectations. For example, they explain that polishing of axe heads is laborious, but it results in greater longevity in the axe because during use the irregularities can act as platforms for unintentional flake removal. Furthermore, polished axes remain in their hafts more consistently. Polish over the entire surface, however, is not necessary and is labor intensive. Were axes polished over their entire surface to increase their exchange and gift value through greater labor investment? In evolutionary approaches, labor investment in goods is cited as a form of prestige technology (Hayden 1998, see Section 2.2.2). Bradley and Edmonds present an insightful review of existing approaches and bring quarry analysis one step further with their in-depth technical analysis that informs a novel yet cautious interpretation with an incorporation of elements of the symbolic and social theory current in the early 1990s.

Chaînes opératoires at quarry workshops

The chaîne opératoireanalysis of quarry materials described by Edmonds (1990) deserves further mention. The chaîne opératoireapproach conceives of lithic reduction as a comprehensive system or "syntax of action" from the origin of lithic material at the quarry to reduction, reuse, and abandonment within a larger context of human action. Sellet (1993: 106) writes that the chaîne opératoireis a "chronological segmentation of the actions and mental processes required in the manufacture of an artifact and its maintenance in the technical system of a prehistoric group. The initial stage of the chain is raw material procurement, and the final stage is the discard of the artifact."

In the realm of lithic production, Shott (2003) and others question whether the chaîne opératoireapproach is notably different from Holmes' century-old concept of "reduction sequence" (Holmes 1894) and Schiffer's Behavioral chain analysis (Schiffer 1975). Two major differences distinguish chaîne opératoirefrom the lithic reduction sequence analysis in the North American tradition. First, while the American reduction sequence focuses solely on lithic production, chaîne opératoireapplies to apprenticeship and expertise relating to allmaterial culture behavior beginning with lithic production but also including ceramics, textiles, architecture, wine-making, and others (Tostevin 2006: 3). Second, even when confined to lithic production, the chaîne opératoireapproachexplicitly attempts to infer the choices and intentionality of the knapper, as well as to capture greater context and breadth by seeking to address the larger context of activity and action.

French archaeology has a long tradition of attributing archaeological variability to choice, stretching back from Boeda (1991) to Bordes to Breuil. This tendency is balanced by an equally strong American-based resistance to attribute variation to cultural choice until all other factors, particularly reactions to environmental stimuli, have been excluded, forming one of the central tensions in the current debate (Tryon and Potts 2006).

Others argue that while attempts to consider the intentionality of the knapper are commendable, in their weaker form sequential models like chaîne opératoirerun the danger of being overly typological and rigidly unable toincorporate behavior that diverges from a one particular linear progression (Bleed 2001;Hiscock 2004: 72).

From the perspective of quarry procurement and workshop activities, production would have proceeded with a goal in the mind of the knapper based on the quality of the raw material as well as organizational issues like technological requirements and mode of transport. For Edmonds (1990: 68) implementing a chaîne opératoireapproach at a quarry workshop appears to have been complicated by an overwhelming presence of flaked stone belonging to early stages production, and a paucity of evidence concerning consumption. It seems that observing a complete "syntax of action" is hampered by the incomplete view of reduction, as the evidence is overwhelmingly from workshops and not from consumption sites. Thus, while quarry workshops have relatively few classes of artifacts the techniques, such as refitting, are seldom practicable when there is an abundance of early stage material and an under-representation of advanced reduction flakes and complete, or near complete, tool forms.

Variability in initial reduction of cores observed at the Great Langdale quarry workshops reflect the available raw material and the quarrying methods used to procure the material, and these frame the starting context for following a chaîne opératoireanalytical model. However, the chaînesequence is often truncated and largely capable of merely determining early reduction characteristics that are basic to all reduction sequence analyses in the tradition of Holmes (1894). For example, at Great Langdale the researchers determine, mostly from platform characteristics, that there was expedient, ad hoc production in one period and more precise and controlled flaking in another. Sequence models seem to be of limited utility in contexts where only initial workshop production is available, a condition that perhaps explains the avoidance of an explicitly chaîne opératoireapproach in the later Bradley and Edmonds (1993) volume. In sum, chaîne opératoireis roughly synonymous with American 'reduction sequence' and Schiffer's Behavioral Archaeology in terms of low and mid-level theory, but in high level theory it is not generally presented except for the theory of chaîne opératoireitself (Tostevin 2006). Given the difficulties of meaningfully applying chaîne opératoireto data based almost entirely on quarry workshop contexts, the concepts will not be attempted in this research.

Interpreting the axe trade

While earlier approaches focused on efficiency and evolutionary schema in a commodified vision of production, Bradley and Edmonds (1993) attempt to take a middle road where they use measures of efficiency and investment observed in workshop contexts in a heuristic manner, but they principally base their interpretations of production on the changing socio-political context of the larger consumption zone. They consider artifacts in terms of dichotomies that probably existed in some form, dividing the circulation of inalienable gifts from alienable commodity production. They seek to consider the implications of gifts in the theoretical terms that relate gift-giving and status acquisition with the political strategizing of elites in Neolithic Britain. Further, they consider the "regimes of value" where gifts and commodities circulate and are assigned value that is a construction of political contexts and not merely a reflection of measurable costs using the concepts of social distance borrowed from Sahlins. Finally, Bradley and Edmonds consider the circulation of axes as wealth goods and the ways in which elites may influence the specialized production of axes (Brumfiel and Earle 1987) and the circulation and consumption in a peer polity situation (Renfrew and Cherry 1986) or through control of deposition (Kristiansen 1984). Ironically, while neoevolutionist approaches are explicitly rejected, one is left with the question: what is theoretically significant about changes observed in the circulation of axes if not the link to evolutionary changes in socio-political organization? In both Edmonds (1990: 66-67) and Bradley and Edmonds (1993), evolutionary explanations are avoided in the analysis of production, but in regional exchange the changes observed attributed to increasing levels of social ranking as indicated by competition over exchange networks and specialized knowledge during the Later Neolithic.

Direct Access

Direct household procurement of goods is largely structured by the geographic relationships between consumer residence and a given resource. Access to products from complementary ecological zones by consumers who undertake a personal voyage to acquire and gather those goods is a form of direct access. For resources that are widely distributed in ecological areas or along altitudinal bands, direct access is a recurring theme in Andean prehistory. The procurement of unique or unevenly distributed or resources, such as salt or obsidian, is a different configuration entirely in a vertically organized region like the Andes, because distant consumers are forced to articulate with production areas far beyond their immediate and complementary neighbors in an altitudinally stratified exchange relationship. This kind of multiethnic, direct household procurement for salt occurs in the Andes to this day (Concha Contreras 1975: 74-76;Flores Ochoa 1994: 125-127;Oberem 1985 [1974];Varese 2002).

Direct access by foragers was the first mode of procurement in the Andes, and this acquisition mode probably dominated in Early Holocene prior to the population growth that permitted the development of reciprocity networks. The procurement of raw materials in a manner that is incidental to other subsistence activities is a more efficient means of acquiring these goods, an activity described as "embedded procurement" by Binford (1979: 279). Communities, ethnic groups, and even prehistoric states appear to have maintained direct access to resources in other zones, and (as is stipulated by the definition of the direct accessmode) this kind of articulation is for direct consumption or redistribution on the level of the corporate or state entity. This is part of a much celebrated pattern in Andean research, a feature known as vertical complementary (Murra 1972), a topic that will be returned to in more detail below. Direct access by states to unusual sources of raw material such as metals and minerals are well documented in the Andes. These include as Inka mine works, and distinctive Inka artifacts and architecture are commonly encountered in association with the procurement areas. In access between herding and agricultural sectors, there is also an ethnographically documented direct access mode described as "ethnic economies". In this direct access mode, ethnic groups will control parallel strips of vertical land holdings, and sometimes non-contiguous tracts, ranging from lower agricultural zones to high puna that may lie several thousand vertical meters above. This pattern is documented on the eastern slope of the Andes for the Q'eros of Cuzco (Brush 1976;Flores Ochoa, et al. 1994) and several communities in northern Potosí in Bolivia (Harris 1982;Harris 1985). The important concept of the direct access organization is that entities that were consuming the goods were directly responsible for acquiring them. If there is inter-household barter or transfer of any kind, then the arrangement likely belongs to a type of reciprocity relationship.

Reciprocity

The institution of reciprocity is important in all societies, and in the contemporary Andes reciprocal relationships are elaborate and permeate village life. It is an arrangement for the transfer of labor or goods that is organized without coercive authority between entities equal in status, although sometimes disputes are settled by community leaders. Andean labor reciprocity includes agricultural work, roof raising, canal cleaning, terrace building, and other services; as such, reciprocity structures the traditional village economy in the Andes (Alberti and Mayer 1974;Stanish 2003: 67). These kinds of reciprocal arrangements are frequently delayed, although compensation can be accelerated through recompense in products. For example, a herder might bring a caravan down to a farming area in the lower valleys and spend some days contributing labor to the agricultural harvest in exchange for some portion of the yield.

In many premodern economic transactions relationships of balanced reciprocity structured these arrangements. Two forms are likely in the Andes, that include (1) a multitude of small, household exchanges creating "down-the-line" artifact distributions (see Figure 2-2), presumably this type of exchange is responsible for the long distance transmission of small, portable goods for much of the pre-ceramic period. A second form consists of (2) barter exchange relationships with regular long distance caravans that articulated with settlements, and perhaps at periodic fairs, that transported goods over potentially greater distances. This mode would effectively consist of unadministered trade. The institution of reciprocity will be explored in more specific contexts below.

Redistribution

The basis of relations between political elites and non-elites in the prehispanic Andes was shaped by redistribution. In Andes during the later prehispanic period, redistributive mechanisms linked elites to non-elites through the redistribution of consumables like coca, and feasts of food and chichabeer in exchange for labor and political support. "The manipulation of redistributive economic relationships among the elite and their retainers, most notably of exotic goods and commodities, stands at the core of the development of Prehispanic Andean complex societies" (Stanish 2003: 68). Often these surplus goods were produced through efficient mechanisms orchestrated by elites, and the benefits and prestige derived from these surpluses would be accrued disproportionately by political leaders.

The central collection of goods for redistribution or use by the state includes taxation which, in the Inka period, was through mit'alabor. With respect to the exchange of lithic raw materials, Giesso (2003) argues that at Tiwanaku household stone tool production was a form of taxation. Giesso cites ethnohistoric evidence referencing the Inka period and argues that the household knapping of projectile points could have contributed to the provisioning of the state armory. The means by which non-local material arrived in the Tiwanaku homeland is unclear, but in the Inka case the raw material was acquired locally or it was provided by the state (Giesso 2003: 377). Earle (1977: 215) argues that redistributionshould be considered as two major groups with leveling mechanisms on one side and complex institutional mechanisms for wealth accumulation on the other (see Section 2.2.4).

Administered Trade

Non-market administered trade was another major means of transfer in the prehispanic south-central Andes. Building on Polanyi's classic definition of non-capitalist economic types, Charles Stanish (2003: 69) describes a form of elite-administered, non-market trade that was capable of procuring non-local goods and that provided wealth to elites as follows. Garci Diez's Titicaca Basin visita, a 16^thcentury Spanish census document (Diez de San Miguel 1964 [1567]), describes how local elites in the Lake Titicaca Basin would have their constituents organize llama caravans for trading expeditions to adjacent regions. In neighboring areas such as the Amazon basin to the east, the Cusco valley, and western slope valleys, agricultural goods such as corn, fruits, and other products were sweeter, faster growing, and more abundant than in the Titicaca Basin. The colonial visitaindicates that, based on the colonial currency, corn in the Titicaca Basin was worth 5.7 to 6.9 times the amount that it was worth in the Sama valley (an area in modern-day southern Bolivia) where it was abundant. Stanish (2003: 69-70) argues that administered trade benefited elites because they were able to appropriate this difference in value, and through feasting and other ceremonial functions, a portion of this wealth was redistributed to commoners. It is important to mention that these same colonial sources indicate that the commoners also organized trading ventures and would take advantage of these elite-organized journeys to conduct private barter exchange on the side. With reference to herders conscripted into elite orchestrated trade caravans "those in Lupaca country 'who had their own cattle [cargo llamas]' (Diez de San Miguel 1964 [1567], f. 13v) went to the coast and to the lomas to barter on their own. …the maize growers on the irrigated coast were eager for the highlander's animals, their wool and meat" (Murra 1965: 201). Thus, elites organized large caravans and apparently possessed the surplus wealth and the camelid caravan animals in advance to initiate the trading expedition, but the herders that they conscripted also engaged in household-level barter. For the elites, their organizational efforts earned them significant wealth and status for a relatively modest outlay of costs. For the herders, it appears that they were able to embed household economic transactions with their mit'alabor service by conducting their side barter activities. Apparently, even the powerful Lupaca elite had to concede some independent trade activity to their caravan drivers. What, then, of the relationship between caravanerosand elites during earlier periods, when elites probably had less consolidated power than during the contact period?

The evidence suggests that "administered trade" was not the first form of long distance caravan exchange. As mentioned above, relationships of balanced reciprocity have long served to articulate herders with those living in complementary ecozones such as sierra agriculturalists, coastal fishers, and residents of the eastern lowlands. But the long distance transport of diffusive goods like obsidian are well-demonstrated and form a continuous network configuration that contrasts with the segmentary, vertically organized exchange between valley and puna (Figure 2-3). Archaeological distributions (Browman 1981;Burger, et al. 2000;Dillehay and Nuñez 1988;Nuñez and Dillehay 1995 [1979]) and contemporary ethnoarchaeological studies (Lecoq 1988;Nielsen 2000;West 1981) attest to the capacity for small scale, household-level organization of multi-week caravan expeditions. This evidence suggests that there were probably at least two major types of long distance caravans operating from the Late Formative onwards. The question then becomes: what was the relationship between household-level caravans and elite-administered trade? Did elites co-opt functions that were previously coordinated on the household level? If elites acquired control of some segment of caravan traffic, what strategies did elites use to wrest control from caravan drivers that, the evidence suggests, were very independently-minded people (Browman 1990: 419-420;Nielsen 2000: 517-520)? These questions concerning the origins and configurations of regional interaction in the south-central Andes are at the center of this discussion of changes in obsidian procurement and the regional circulation of goods in prehistory on the perimeter of the Lake Titicaca Basin.

Vertical complementarity

The contrasting ecological zonation found in low-latitude mountain regions worldwide has resulted in distinctive social configurations that appear to reduce risk, broaden the selection of products available in a given zone, and provide opportunities for strategic advancement by particular individuals or groups. These configurations have been investigated in two broad sets by Andeanists. First, there are a number of scholars who address vertical complementarity as a general process that is comparable with other mountain regions of the world. Second, there is a particular configuration known as "Vertical archipelagos" first described by John Murra (1972) that has been widely discussed in the Andean literature.

Horizontal complementarity

Soon after Murra published his 1972 paper about vertical complementarity, researchers began noting that vertical complementarity is only one of a number of strategies employed in the Andes. A different kind of geographical interaction pattern, one that stays within broad regions such as the altiplano or the littoral, has been called horizontal complementarity. Contrasted with Murra's vertical complementarity model, in horizontal complementarity polities would directly control many parcels in a given niche. Here, the adaptationalist argument is somewhat less obvious since a horizontal complementarity strategy seems redundant unless particular resources were only available in one sector of a given horizontal territory. This phenomenon could reflect a cultural mechanism for the continued social integration of communities distributed widely across a vast region. An analogous situation can be observed in the culturally-constructed Yanamamö trade for ceramic wares, maintained to provide a social catalyst for villages to come together for feasting and marriage-making, despite the risk of conflict and treachery (Chagnon 1968).

Relations of horizontal complementarity between coastal valleys have been observed on the littoral (Netherly 1977;Rostworowski 1977;Shimada 1982), and for the higher altitude altiplano area where this kind of organization is referred to as the "altiplano mode of economic integration" (Browman 1977) and, to a lesser extent, the modern "extended type of Andean zonation" (Brush 1977: 12-16;Gade 1975). The extended type takes place in regions of expansive, contiguous production where exchange forms the basis for circulating products from other zones. In the expansive altiplano where there are fewer impediments to travel and, with the domestication of camelids, relatively low transport costs with cargo animals, materials may have been conveyed over substantial distances.

Figure 3-4. Subsistence exchange for products by ecozone versus single-source, diffusive goods.

A general schematic of these contrasting relationships is shown in Figure 3-4. While there is a great deal more complexity and variability to economy and exchange than is communicated in Figure 3-4, for example tubers are grown in the high elevation zones and herding does occur below 3800 masl, the purpose is to highlight the contrasting network characteristics. These two characteristics include

(1) Subsistence exchange.The acquisition of products available by zone contrasts

(2) Diffusive.The network for goods that radiate diffusively, such as obsidian and salt.

While the mixed agropastoral strategies are also very common, particularly in ecotone areas such as the puna rim, the subsistence exchange that articulates dedicated pastoralists with agriculturalists has been documented ethnographically in many studies of which only a selection are shown in Figure 3-4 (Bastien 1978;Brush 1977;Custred 1973;Flores Ochoa 1968;Palacios Ríos 1981;Winterhalder and Thomas 1978).

Ecological complementary has long served to transfer goods between ecozones, however the movement of goods laterally through areas of homogeneous resources, such as horizontal complementarity across the puna, implies other mechanisms of transfer. In addition to strategies described previously, it has been proposed that large periodic markets are a possible solution to the problems of social and economic integration among agropastoralists living in widely distributed settlements.

Browman (1990: 405-411) reviews the evidence for prehispanic and colonial period markets in the Peruvian and Bolivian altiplano. The colonial period aggregations in the Andes are products of historical circumstances, however Browman's evidence suggests that periodic fairs in some form were a feature of the prehispanic economy. While evidence concerning the actual goods exchanged at periodic fairs during the prehispanic period is scarce, these events could have been an effective way for obsidian to have been distributed in highland Peru and these fairs will be discussed in more detail below. Seasonal or annual gatherings are also ethnographically known among foragers in arid regions of the world with low population densities (Birdsell 1970: 120;Steward 1938). Social aggregations in some form can be expected to date back to the foraging period and these aggregations probably included, among other activities, the exchange of goods.

Evidence for barter, markets, and marketplaces in theAndes

"They did not sell… nor did they buy… they thought it was a needless operation" and all universally planted what they needed to support their households and thus did not have to sell foodstuffs, nor raise prices nor did they know what high prices were…(Garcilaso 1960 [1609]: 153; cited in Murra 1980: 142).

Was obsidian exchanged through a market system reflecting supply and demand in the prehispanic Andes? Were exchange specialists present in the prehispanic Andean highlands? If so, when did they appear and what did they transport? While extensive exchange has been documented in the prehispanic Andes, it is widely believed by Andeanists that exchange in the prehispanic central Andes was not based on market institutions. Building on the typology developed in Chapter 2 following Renfrew(1975)and Salomon(1985), differing degrees of specialization and independence can be expected to have existed among actors in exchange relationships (Figure 2-2andFigure 3-3). If specialized traders were present in prehispanic Andes, how did they interface with state authority during the Middle Horizon and Late Horizon, and what was their position during periods of regional conflict like the Late Intermediate Period?

Much of the evidence supporting the alleged lack of market-based exchange is derived from studies of Inka economic organization, where ethnohistorical accounts and archaeological datasets converge. A great deal has been written on the topic of Inka economy, and obsidian exchange was relatively diminished during this period, therefore this discussion will be limited to a few relevant issues regard exchange specialization. Several of the sixteenth century chroniclers are clear that while barter was widespread, the barter values of goods did not reflect fluctuations in supply and demand as in a market economy. However, the lack of consensus on the issue of markets and commerce during the Inka period stems from inconsistency in the cronistasthemselves. As reviewed by Murra(1980: 139-152)and LaLone(1982)the denial of a market exchange by Garcilaso de la Vega (quoted above) can be contrasted with numerous accounts of large and small markets, and a long tradition of barter exchange of various types.

The issue of Late Horizon marketplaces and market exchange is explored here because one of the principal questions that may be considered with changing obsidian distributions through time is the possible role of commercialism in prehispanic Andean exchange. The appearance of exchange specialists, such as freelance caravans moving certain commodities and responding to the changes in barter values that result from surpluses and shortages, would have presented a mode of transport distinctive from that of local reciprocal exchange or regional or state redistribution.

The vertical archipelago model functioned as an alternative to trade for goods from neighboring areas because "regional differences in production were, by preference, handled by means of colonization instead of through barter or trade."(Murra 1965: 201). As mentioned, Stanish argues that Murra initially excluded exchange mechanisms because of a perceived association between exchange and market economies. Further it can be argued, building on Appadurai(1986: 33), that in certain contexts of ranked or stratified societies with elaborate redistribution mechanisms, market systems of exchange represent a threat to the centralized ideological power of redistribution. "There is great advantage to leaders who are able to portray their resource-control strategies as reciprocity, redistribution, and generosity. Non-centralized resource-control strategies are, by definition, not 'control' strategies"(LaLone 1982: 296). If centralization is a principal determinant of state control on market exchange, were the peripheries involved in greater numbers of barter transactions?

Limitations of ethnohistory and ethnography

Ancient economy in the Andes has been most fruitfully studied by combining archaeological evidence with ethnohistoric and contemporary sources. General models of great importance to Andean studies such as vertical complementarity, the question of the commerce in the prehispanic economy, and a structure of dual organization in the Inka administration are examples of models emerging from ethnohistoric sources but with empirical support from archaeological research. Ethnohistorically based models also have their limitations in that they can unduly influence interpretation much in the way that the "tyranny of ethnography"(Wobst 1978)should not necessarily define the range of archaeological possibility and inference. Ethnographic sources are valuable for the evidence of pastoral patterns, the priorities of caravan drivers, and the articulation between mixed and specialized pastoral and agricultural practices. However, modern features including the presence of the cash economy, markets, truckers plying the highways, and various modern job opportunities impact the structure of exchange relationships and caravan transport(Browman 1990;Nielsen 2000).

Ethnographic studies of contemporary llama caravan drivers are focusing, by necessity, on relatively marginalized communities that are sufficiently conservative to continue to herd llamas despite a variety of often more lucrative alternatives (Lecoq 1988;Nielsen 2000). Scholars have noted, however, that caravan drivers enjoyed relatively high status and autonomy in the late prehispanic and early colonial period which contrasts strongly with the economically marginalized modern day caravanero(Murra 1965). Furthermore, herding has become relatively low status in many regions of the contemporary Andes because the economic focus has moved downslope since Spanish contact due to the growth of the coastal economy and the importation of various low altitude crops and livestock. In other words, the prominence of caravan drivers as central economic agents has been greatly diminished in recent centuries, and ethnographically documented interactions with agriculturalists is one circumstance in which this relative shift in power may result in distorted perceptions of prehispanic interaction patterns. The relatively high status accorded to truck drivers and other purveyors of goods and information in contemporary Andean villages was likely to have been ascribed, instead, to the relatively cosmopolitan drivers of llama caravans during prehispanic times.

Estimating travel velocity

A computer model for estimating travel speed based on topography, where velocity over a segment of trail is calculated as function of slope, could be derived using the function presented by Tobler (1993) for hiking and horseback riding (the source of cost paths shown in Figure 3-5). While these topography based calculations have serious limitations (Connolly and Lake 2006: 252-255), for general estimates over larger regions with measurable changes in terrain steepness these estimates are superior to the simple use of slope for estimating velocity. Such models would preferably be derived using original data from fieldwork, perhaps based on a contemporary study that takes into account the size and weight of the cargo animal, the amount and type of cargo, and the performance of the cargo animals based on trail conditions mapped using GPS receivers.

In the course of ethnoarchaeological fieldwork accompanying a llama caravan in Bolivia, Nielsen (2000: 449;2001: 184) notes that there were differences in the going and returning portions of a 2-3 month caravan journey that had implications for the overall travel speed. The out-going trip involved visits with companions and a variety of rituals at propitious locations along the route. During the return journey, in contrast, no rituals were performed but the animals moved more slowly because they were carrying large loads of produce uphill from the eastern lowlands; and they had been traveling for months and reportedly their feet hurt. Thus the lack of ritual performance and visiting and bartering saved time, but the walking speeds were slower, breaks were longer, and layover rest days were more frequent and longer.

Evidence of relative travel distances in the region

In the Mantaro region of the central Andes, Earle (2001: 310) notes that long distance exchange (classified as taking place over a distance of 50 km or greater, to lands beyond those held by the local ethnic group), rarely includes staple items. During the Late Intermediate and Late Horizon, items that were found in the Mantaro area include items of metal and shell described as "wealth items", emphasizing the political nature of long distance exchange in this period.

While Colca valley obsidian was primarily conveyed throughout the Titicaca Basin during prehispanic times by unspecified groups, during the colonial period Colca valley polities are known to have been dominant caravan operators in the region. Residents of the Colca valley owned large camelid herds and they were responsible for extended caravan journeys to the altiplano during the Colonial period. Documentary evidence shows that the Collaguas from the main Colca valley initiated caravans to transport products, such as Arequipa wine to Cusco and Canas, and Colca corn to "wherever they would like to sell it" (Crespo 1977: 56). A testament to the role of the Collaguas, and the Colca valley in Arequipa more generally, comes from Toledo's (1924 [1570-1575]) visita generaldescribing populations of Colca community members resettled as farmers in the new city of Arequipa, Yanahuara, and environs. Toledo states that these Collaguas mitimaesgroups should produce wine in these lower-altitude areas for transport to Cusco and to the mines of Potosí in Bolivia over 700 km to the south-east (Málaga Medina 1977: 114).

Yapa and over-reciprocation

Barter relationships are often cemented with a yapa:a little bonus given to the buyer that takes the form of an over-reciprocation to assure future transactions (Browman 1990: 421;Sahlins 1972: 303). The magical powers attributed to the yapanotwithstanding, Sahlins' (1972: 308-314) develops a functional economic explanation for over-reciprocation where it serves a similar mechanism to price fluctuations in market-based societies. When an over abundance of product A relative to product B exists in a barter situation based on traditional equivalencies (hence, a lower value for A may result, in a market system), the provider of product A may over-reciprocate and thus, based on the morality of reciprocal arrangements, guarantee future compensation from the trade partner.

The primitive trade partnership is a functional counterpart of the market's price mechanism. A current supply-demand imbalance is resolved by pressure on trade partners rather than exchange rates. Where in the market this equilibrium is effected by a change in price, here the social side of the transaction, the partnership, absorbs the economic pressure. The rate of exchange remains undisturbed - although the temporal rate of certain transactions may be retarded (Sahlins 1972: 311).

The discrepancy that must be resolved synchronically in neoclassical market economics is resolved diachronically in reciprocal arrangements (Danby 2002). Browman (1990: 421) does not believe the over-reciprocation device described by Sahlins is in evidence in the Andes. As Browman observes, there is ethnographic evidence that suggests that barter rates do, in fact, fluctuate in response to supply and demand. The arrangement described above is one possible configuration that occurred in prehistoric circumstances, however, and it is a possible means of assuring the long term persistence of exchange relationships (Burchard 1974;Mayer 1971).

Seasonal fairs and the temporality of caravans

If seasonal fairs and aggregations were a feature of the prehispanic altiplano, as discussed by Browman (1990), interactions may have taken notably different forms in those contexts. Seasonal fairs may have had the significance of religious festivals in the contemporary Andes where the devout sometimes travel for weeks in order to arrive at auspicious times. Fairs and cultural occasions may, then, have been blended with economic transactions.

Scheduled festivals with elaborate dances, music, and costumes are a major cultural contribution in contemporary altiplano communities like Paratía (Flores Ochoa 1968) and despite the lack of simple material correlates for archaeological study, cultural items like song and dance were probably significant features in a variety of prehispanic reciprocal exchange contexts (J. Flores Ochoa 2005, pers. comm. July 2005). Despite the relative marginalization of altiplano cities in the modern economy (or perhaps a reflection of this marginalization), traditional festivals endure as important cultural features in the Titicaca Basin. Citing early twentieth-century sources, Browman (1990: 409) reports that at major shrine at Copacabana, Bolivia, between 40,000 and 50,000 "traders" would converge at times scheduled to coincide with ceremonies at the shrine.

If economic transactions occurred in association with these festivals in prehispanic times, either as a central feature or relegated to the periphery of the cultural events, the transactions may have assumed certain characteristics of marketplace exchange. These characteristics would have included public knowledge of barter equivalences and perhaps more immediate, synchronic exchange due to the short time period of convergence at the festival. As mentioned, however, marketplace concentrations do not necessarily imply true "market economies" with fluctuating prices reflecting supply and demand (LaLone 1982). Assuming that economic transactions that may have occurred at these fairs did not create moral conflict (by debasing sacred ceremonies with lowly economic transactions, in a Euro-American perspective) they would have created an excellent context for the transfer of both cultural goods and prestige items, and for the control of certain exchange practices by administrators or elites. Nevertheless the problem remains that dedicated agriculturalists with harvest goods for exchange would have been absent from these fairs on the altiplano because dedicated agriculturalists would not have the schedule or the herd demographics that would have permitted them to initiate long distance caravans. Therefore a variety of strategies probably developed to allow the transfer of products with the emergence of caravans that traveled, on the large scale, according to schedules dictated by seasonal gatherings, harvest schedules, and other economic and cultural circumstances. These developments imply the emergence of something of a continuum between the more alienable exchange that occurred in seasonal gatherings, and more inalienable barter that occurred in the intimate exchange context of compadrazgorelationships.

Availability, demand, and mobility

Chivay was largely conveyed into the Lake Titicaca area by Titicaca Basin communities and polities that were organized around the lake and the adjacent broad altiplano. For sites in the Lake Titicaca Basin, the database shows that 453 obsidian artifacts have been sampled from all time periods, and 408 (90%) of the samples were of the Chivay obsidian type. Another interesting aspect to this pattern is that the proportion of Chivay obsidian holds true for the north Titicaca Basin as well as the south when the two areas are considered separately. Using Bandy's (2005: 92) division of the Titicaca Basin where the site of Camata and northward are considered the North Basin, and with the South Basin extending as far south as Khonkho Wankane and south-west to Qillqatani, all obsidian samples in the region were aggregated from the entire prehispanic period. The LIP site of Cutimbo, though slightly south of Camata, was joined with the North Basin sites while Incatunahuiri and the Ilave valley sites were counted with the South Basin.

Table 3-3. Obsidian in the north and south Titicaca Basin by counts and percents.

These patterns reveal that Chivay obsidian accounts for approximately 90% of obsidian from the Titicaca Basin, with a greater presence of Alca obsidian in the North Basin. It seems that the presence of obsidian from alternative sources, whether it was the Tumuku source (still unlocated) or other obsidian sources further to the south, counter balances the access to Alca type in the North Basin. This pattern, with heavy use of Chivay obsidian in the South Basin, reflects overall integration in the Titicaca Basin through prehistory as well as the lack of high quality obsidian sources with large nodules south of the Chivay source, until one arrives at the Zapaleri source close to the frontier of Bolivia, Argentina and Chile, located 700 km to the south of Lake Titicaca (Yacobaccio, et al. 2004: Fig. 1). It has been noted that, in cultural terms, the Chivay distributions are especially linked to areas integrated by the Tiwanaku state, the Pukara polity, and with their predecessors: the Middle Formative communities linked by Yaya-Mama stylistic features (Burger, et al. 2000). However, what is particularly compelling about the evidence from obsidian is that these social and economic links in obsidian exchange appear to predate the cultural-stylistic links and become defined in the Terminal Archaic roughly 1000 years earlier than regional evidence of the Yaya-Mama stylistic attributes that first appear at Chiripa in the southern Lake Titicaca Basin.

The distribution of Alca material is confined by the availability of Quispisisa on one side and Chivay on the other, but nevertheless Alca obsidian was transported the furthest with material during the Middle Horizon being conveyed as far as the Wari sites of Huamachuco and Marca Huamachuco near Cajamarca (Burger, et al. 2000: 336). Alca material was also transported the furthest distance at an early date, as it was conveyed 769 km to Chavín de Huantar during the Early Horizon where it was found in both elite and commoner contexts (Burger, et al. 2000: 313-314). Quispisisa predominates in Wari assemblages but it also circulated widely before the Middle Horizon, such as the 589 km to Chavín de Huantar during the Early Horizon.

Terrain adjacent to source

The altitudes of obsidian consumption sites (XFigure 3-6X) also reflect the terrain adjacent to each of the sources. The Quispisisa source is in an area with deep river valleys and a number of the sites sampled are from lower elevation or coastal contexts. The Alca source is similarly close to deep river valleys, but it also borders the altiplano and the much of the Alca samples came from the highlands of the Department of Cusco. The Chivay source is on the periphery of the broad altiplano and with no major altitude loss it was possible to transport material to a variety of sites that include Pikicallepata to the northeast and Qillqatani to the southeast. Further detail on these obsidian distributions are described below, and are published elsewhere (Burger, et al. 2000; cited in Craig 2005: 908-916;Frye, et al. 1998;Giesso 2000).

Small quantities of material and regional models of exchange

The actual volume or weight of obsidian at Qillqatani is relatively small. Obsidian from the Chivay source appears in small quantities in nearly every stratum in the approximately 8000 year sequence. The most informative data on long distance exchange come not from the total mass of obsidian, but from the variability in the relative percentage of obsidian flaked and obsidian tools in each lithic assemblage through the sequence. Nevertheless, the weight of obsidian tools at Qillqatani totals 43 g, and the sum of the weight of obsidian flakes is 382 g out of a total of 11,085 g of lithic material. Thus, the entire quantity of obsidian excavated at Qillqatani is only about 1.5% of the cargo that could be carried by a single llama.

These figures are meant to highlight a central issue with obsidian studies overall: the actual quantities of obsidian encountered and evaluated from the consumption sites throughout the south-central Andes are relatively low. The significance of obsidian circulation over the larger region is not matter of weight or volume, but rather a question of consistency and changes in the proportions of particular sources utilized over time. These data from Qillqatani underscore this issue. A comparison of the persistence of non-local obsidian at Qillqatani as of level 24 (X

Table 3-6XandXTable 3-7X) with the non-local obsidian at Asana (XTable 3-4X) during earlier periods of the Archaic, suggests that on a regional scale mechanisms of exchange, or direct acquisition, were more intermittent during the earlier Asana phases. In contrast, Qillqatani has high quality cherts and low quality Aconcahua type obsidian available in the immediate proximity of the rock shelter. Thus, the question becomes: why transport Chivay obsidian 200 km when alternative materials are locally available? Further, why was the transmission of Chivay obsidian so consistent through time? In this perspective the low but consistent quantities of Chivay obsidian that were conveyed throughout the south-central Andean highlands during the prehispanic period can be seen as a gauge of highland interaction and horizontal complementarity, with wider implications for exchange.

IlaveValley

In the Ilave valley, obsidian was scarce prior to 3300 BCE, but it appears in a number of Terminal Archaic and Formative contexts after that date. Diagnostic projectile points from the Ilave area reveal a dramatic change in material type with the Terminal Archaic.

Figure 3-9. Comparison of projectile point counts in the Ilave Valley and the Upper Colca.

Using only diagnostic projectile points from the Klink and Aldenderfer (2005) point typology, these data reveal a shift to greater use of obsidian with series 5 projectile points. Following the point typology, all series 1 through 4 points are diagnostic to the Terminal Archaic or earlier, except for types 4C and 4E which have been excluded from this analysis. The lower part ofXFigure 3-9Xreveals data classified into the same three groups, but with data from the Chivay obsidian source area resulting from the 2003 Upper Colca project. Comparing these two datasets reveals that with the advent of Series 5 points in the Terminal Archaic after 3300 BCE there is a sudden upswing in obsidian use in the Ilave consumption zone that corresponds perfectly with a dramatic shift in projectile point production at the Chivay source area itself. There appear to have been pan-regional changes occurring with the widespread adoption of series 5 style projectile points, the use of obsidian, and these changes are possibly related to the greater use of the bow and arrow.

Jiskairumoko (95-189)

The site of Jiskairumoko was excavated using a broad, horizontal décapage technique between the years 1999 and 2002, and Craig's (2005) dissertation forms the site archive. Radiocarbon dates fromexcavation work at Jiskairumoko range from the Late-Terminal Archaic transition with a date of 4562±73bp(AA58476; 3520-3020 BCE)through to the end of the Early Formative, with a date of3240±70bp (Beta-97321; 1690-1390 BCE). Note that Craig (2005) has the Terminal Archaic dating to 3000-1500 BCE, while in the Upper Colca Project and in this dissertation the period dates to 3300 - 2000 BCE All references to the "Terminal Archaic" have been adjusted to the latter time range in this document unless otherwise noted.

Craig and Aldenderfer chemically characterized 68 bifacially-flaked obsidian tools from excavated contexts at Jiskairumoko (96% of all obsidian tools from Jiskairumoko) by sending these items to M. Steven Shackley at the UC Berkeley Archaeological XRF Lab(Craig 2005: 513, 908-916). The samples were compared with four geological samples that provided to Shackley from nodules that I had collected from Chivay source in 2003. Three of the nodules provided to Shackley were from the Maymeja area and one was from east of Cerro Hornillo. The XRF results showed that 97% of the Jiskairumoko obsidian tools (n = 66) were from the Chivay source and 3% (n = 2) were from the Alca source. These values diverge slightly from obsidian type distributions in the Titicaca Basin more generally (XTable 3-3X), where 90.5% (n = 466) of all of the obsidian artifacts tested to date from the Titicaca Basin are Chivay type. These data indicate that the people at Jiskairumoko were more intensively using Chivay obsidian in the Terminal Archaic and Early Formative than were Titicaca Basin residents over all, especially in contrast to the variety in obsidian types that emerge from samples dating to later times.

Obsidian artifacts from excavations at Jiskairumoko reveal that obsidian was used in similar proportions for projectile points from excavated contexts as for points from surface contexts in the Ilave valley. Craig(2005: 685)observes that 18% (n = 54) of the excavated Jiskairumoko projectile points are made from obsidian. He also notes that 50% of these have edge modification in the form of serration or denticulation while only 15% of non-obsidian points have edge treatment, a statistically very significant pattern that he attributes to the symbolic importance of this material. Obsidian was found, along with other lithics and a carved camelid effigy, in Burial 1 at Jiskairumoko in the grave of an elderly adult female with cranial deformation, a primary deposit dating to the Terminal Archaic or 3019-2859 cal BCE(Craig 2005: 680-682). Graves excavated in the Ilave valley area also contain a variety of non-local grave goods including obsidian, lapis, and gold, but non-local grave goods only occur in contexts dating to the Terminal Archaic and later.

Early Archaic (circa 10,000 - 7,000 BCE)

Evidence from the Early Archaic in the south-central Andes is slim, but it is accumulating gradually. The available data suggest that during this time period human groups went from initial exploration of the highlands to more stable, year around occupation of the sierra and puna. The best evidence from the highlands comes from a handful of stratified sites in the region with Early Archaic components, as well as distributional evidence from archaeological survey work(Aldenderfer 1997;1998;1999;2003;Craig 2005: 452-484;Klink 2005;Nuñez, et al. 2002;Santoro and Núñez 1987;).

A regional study of projectile points from excavated contexts by Klink and Aldenderfer(2005: 31, 53)noted that projectile point styles diagnostic to the Early Archaic (Series 1 and Types 4a, 4b) and the Early-Middle Archaic transition (Type 2a) have a broad geographical distribution. These types are found throughout a region that includes the littoral, western sierra, and puna areas of extreme northern Chile and southern Peru, and as far north as Pachamachay cave in the Junin puna(Rick 1980). Given the low population densities of that time period, this wide regional stylistic distribution suggests that a high degree of mobility was being practiced in the Early Archaic and first part of the Middle Archaic. Further to the north, in contrast, raw material types in the Junin puna of central Peru suggest to Rick(1980)that very low forager mobility was occurring throughout the early preceramic period. Early Archaic obsidian distribution data largely confirm with the model of high mobility and show that humans found good sources of lithic raw material in the sierra early, and then transported the material or exchanged it widely from a relatively early date.

Current paleoclimate evidence indicates that glaciers advanced during the late glacial between 11,280 and 10,990¹⁴C yr bp, and then, despite cool temperatures, the glaciers receded rapidly, perhaps as a result of reduced precipitation(Rodbell and Seltzer 2000). Glaciers were in approximately modern positions in southern Peru by 10,900¹⁴C yr bp (circa 11,000 cal BCE). The Early Archaic Period, with reference to diagnostic projectile point styles(Klink and Aldenderfer 2005), begins at circa 9000 cal BCE During the Early Holocene and the first part of the Early Archaic conditions were wetter and cooler than modern conditions. Subsequently, during the latter part of the Early Archaic, the climate began an episode of long-term aridity that lasted through the Late Archaic(Abbott, et al. 1997;Argollo and Mourguiart 2000: 43;Baied and Wheeler 1993;Paduano, et al. 2003: 272). Opportunities in the highlands for human foraging groups were created by a number of new ecological niches for plants and animals that opened up during the Early Holocene. These niches represented a resource pull for mobile foragers that countered the increased difficulty of subsistence in the hypoxic, high altitude environment faced by the non-adapted early settlers in the highlands(Aldenderfer 1999). A review of the evidence for forest cover on the altiplano during the Archaic, with deforestation occurring as a result of pastoral intensification, is provided by Gade(1999: 42-74).

During the Late Pleistocene lacustrine period, paleo-Lake Titicaca (Lake Tauca) was much larger but only a few meters higher than is modern Lake Titicaca (Clapperton 1993: 498-501). Radiocarbon dates on shells show that Lake Tauca was probably still present as late as 10,080¹⁴C yr bp (or 9900 cal BCE). Sediment cores from Lake Titicaca indicate that there was an increase in sub-puna vegetation and fire from vegetation prior to 9000 BP (Paduano, et al. 2003: 272). Evidence from paleoclimate records and fluvial geomorphology point to a time of increased aridity and salinity in Lake Titicaca, with short, episodic moist spells beginning around 8000 cal BCE and continuing through the Middle Archaic and Late Archaic Periods (Rigsby, et al. 2003;Wirrmann, et al. 1992). The climatic data for this time suggest that with deglaciation in the Early Holocene a resource niche opened up that exerted a pull on plant and animal species towards the high altitude regions, and that early human groups responded to these opportunities by colonizing the high Andes.

Middle Archaic (7000 - 5000 BCE)

The Middle Archaic Period, as with the preceding period, is still poorly understood in the region as very few highland sites containing stratified deposits have been studied from this period. In the Lake Titicaca Basin paleo-climatic evidence points to significant aridity, a lake level approximately 15m below the current stand, and high salinity in Lake Titicaca that is comparable to that of modern day Lake Poopó(Abbott, et al. 1997;Wirrmann and Mourguiart 1995). Human occupation during the Middle Archaic in the Lake Titicaca Basin was notably higher than in the preceding period, but research shows that settlement continued to occur in the upper reaches of the tributary rivers and not adjacent to the shores of the saline Lake Titicaca(Aldenderfer 1997;Klink 2005).

Late Archaic (5000 - 3300 BCE)

The Late Archaic in the south-central Andes signals the beginning of economic changes in the lead-up to food production, and furthermore the first signs of incipient social and political differentiation are evident in a few archaeological contexts. Some of the obsidian samples reported by Burger et al(2000: 275-288)with possible Late Archaic affiliations are from surface contexts at multicomponent sites and it is therefore difficult to confidently assign these samples to any particular period of the Archaic.

Discussion and review of the Archaic Foragers period

The transport of obsidian from both the Chivay and Alca sources fluctuated during the Archaic Foragers period, and the distribution remained confined to the sierra and altiplano areas of the south-central Andes. The small and irregular quantities of obsidian consumed throughout the region could have been procured and transported by mobile foragers, or conveyed through down-the-line exchange networks. Conceivably exchange could have taken place a seasonal gatherings as well, based on analogy from other foraging groups worldwide, although there is no direct empirical support for such gatherings in the south-central Andean Archaic. At Asana, the most well-stratified highland Archaic site investigated to date, evidence of non-local obsidian was intermittent and consisted of very small quantities of material in a pattern that is perhaps exemplary of the discontinuous nature of regional exchange during this time.

Obsidian from the Quispisisa source (340 linear km to the north-west of the Chivay source), was likewise used primarily in highland contexts during the Archaic Foragers period, particularly in rock shelters excavated by MacNeish and colleagues in the central highlands. While Quispisisa material was circulated at a number of preceramic coastal sites(Burger and Asaro 1978), current evidence suggests that those contexts post-date 3300 cal BCE (i.e., cotton preceramic) and are therefore Terminal Archaic in the terms used here. It appears that while Quispisisa material was used widely on the coasts subsequent to the Archaic Foragers period, material from Chivay and Alca were virtually always confined in the highlands with the exception of the earliest obsidian evidence of all: Alca at Quebrada Jaguay. In the Archaic Foragers period, as in later periods, the evidence from obsidian is contrary to the widely-discussed Andean vertical complementarity models, because obsidian distributions suggest that the movement of people or products between ecologically complementary zones was not widespread.

Why an "Early Agropastoralists" time block?

In lieu of the traditional preceramic / ceramic divide in archaeology, the "Early Agropastoralist" time block was defined for this project because, in many ways, the conditions during the final millennium of the Archaic had more in common with events in the Formative than with the preceding Archaic Periods. Differentiating sites as "Early Agropastoralist" beginning in the Terminal Archaic requires that one delimits a firm boundary on a process that was millennia in the making. Considering the Terminal Archaic as the beginnings of agropastoralism, and thereby linking it to the attendant settlement distribution that includes series 5 projectile points, connects cultural and economic evidence from throughout the region with a generalized estimate of when food production took hold in terms of scheduling, mobility, and prioritizing the needs of agricultural planting and herding. As mentioned, the term "Early Pastoral" is not meant to imply that no food production occurred before this date and hunting and gathering did not persist after this date. Indeed the current evidence suggests that camelids were first domesticated sometime during the Middle or Late Archaic, probably after 5000 BCE (Browman 1989;Kadwell, et al. 2001;Wheeler 1983;Wing 1986). The "Early Agropastoralist" period refers to a period after 3300 BCE that features a predominantly food producing economy in the highlands including intensive pastoralism, as well as seed-plant and tuber cultivation. These changes in food production may have been linked to the accumulating evidence of increased rainfall and shortening of the dry season beginning circa 2500 cal BCE (Baker, et al. 2001;Marchant and Hooghiemstra 2004;Mourguiart 2000). These changes in economy are joined by evidence of increased sedentism, widening stylistic distributions pointing to long distance cultural integration, and the beginnings of social differentiation apparent in architecture and grave goods. The circulation of obsidian was linked to these phenomena because increased regional interaction was perhaps articulated through camelid caravans, although the presence of caravans in the Terminal Archaic is being explored, not assumed, in this study.

In the Titicaca Basin, the changes incurred between the Terminal Archaic and the Late Formative are monumental. However, from the perspective of the Chivay source the intensification revealed archaeologically, both at the source and in the consumption zone, is notable beginning in the Terminal Archaic, and the intensification does not change notably throughout the Formative Period. Defining the ending of the "Early Agropastoralist" period as the end of the Late Formative is similarly problematic. By the Late Formative, the economic influence of Pukara and other regional centers probably impacted the peoples of the Upper Colca, but direct evidence returning from Pukara, only 140 km away, is scarce in the Colca. In contrast, during the Tiwanaku times, regional states with socio-economic impacts over hundreds of kilometers dominated both the circulation of goods like obsidian, and regional settlement organization.

Terminal Archaic (3300 - 2000 BCE)

The Terminal Archaic ushers in a suite of social and economic changes in the south-central Andes and, consistent with these developments, obsidian begins to circulate in significantly greater quantities during this period. Obsidian is increasingly used for projectile points during the Terminal Archaic, a trend that continues into the Formative Period (Burger, et al. 2000: 294).

Regional patterns in Terminal Archaic sites are somewhat difficult to assess from surface finds because the Terminal Archaic is lacking in exclusive diagnostic artifacts in both the lithic or ceramic artifact classes. As is shown inXFigure 3-10X, the most common projectile point styles that belong to the Terminal Archaic, such as Types 5B and 5D, also persist through the ceramic periods, leaving only type 5A and part of type 4F as diagnostic to exclusively the Terminal Archaic (Klink and Aldenderfer 2005: 48). Furthermore, by definition, the Terminal Archaic is a preceramic period, which precludes a ceramic means of assigning chronology. From site organization characteristics, a site might be considered to be a Terminal Archaic site if it has pastoralist attributes but it is aceramic and has series 5 projectile point types represented that belong, at least partially, to the Terminal Archaic.

The beginnings of the Andean agropastoral strategy are apparent during this period at sites like Asana where seasonal residential movement occurred between the high sierra and the puna (Aldenderfer 1998: 261-275;Kuznar 1995). Another attribute of the Terminal Archaic at Asana is a disappearance of ceremonial features. Evidence for a shift from hunting to pastoralism comes primarily from evidence of corrals (Aldenderfer 1998), from changes in the ratio of deer to camelid remains, and from the ratio of camelid neonate to adult remains. At sites where the process has been observed, the transition to full pastoralism at various sites in the Andes is usually perceived as a gradual process dating to sometime between 3300 to 1500 BCE At Qillqatani, however, the transition was relatively abrupt and it occurred in level WXXIV that dates to approximately 2210-1880 BCE (XTable 3-1X).

Early Formative Period (2000 - 1300 BCE)

In this time period, new socio-economic patterns became well established in the south-central Andes while the distribution of Chivay obsidian was at its maximum both in geographic extent and in variability of site types. During this time period, societies were characterized by sedentism, demographic growth, increased specialization, and early evidence of social ranking(Aldenderfer 1989;Craig 2005;Stanish 2003: 99-109).

At sites like Jiskairumoko in the Titicaca Basin, architecture from the Terminal Archaic consisted of pithouses with internal storage, ground-stone, and interments with grave goods that included non-local items (like obsidian) that were presumably of value(Craig 2005). During the Early Formative around 1500 BCE this architectural pattern gives way to larger, rectangular, above-ground structures that lacked internal storage.

As reviewed by Burger et al. (2000: 288-296) using the Ica "Master sequence" chronology under the roughly contemporaneous "Initial Period" (though the Early Formative ends 300 calendar years earlier), the distributions of obsidian are notable in their extension both north and south from the Chivay source, and in their concentrations at early centers like Qaluyu. Obsidian from Chivay also persists on the Island of the Sun in the Early Formative(Stanish, et al. 2002).

Middle Formative Period (1300 - 500 BCE)

During the Middle Formative Period, social ranking became established in the Titicaca Basin. The changes are most evident in the settlement structure as some regional centers grew to become far larger than their neighbors and feature sunken courts, mounds, and specialized stone and ceramic traditions. Stanish(2003: 109-110)interprets these changes in terms of an ability of elites to mobilize labor beyond the household level.

The stylistic evidence suggests that during the Middle Formative the north and south Titicaca Basin were relatively separate spheres, with Qaluyu pottery in the north and fiber-tempered Chiripa ceramics in the south extending only as far north as the Ilave river. However, Chivay obsidian is encountered in both the North and South Basin. Christine Hastorf (2005: 75)suggests that by the end of this period (the Early Upper Formative) evidence of ethnic identity and ritual activity is supported by ritual architectural construction and non-local exchange goods. It is further inferred that "Plants such as coca ( Erythroxylumsp.), Anadenanthera ( A. colubrine, A. peregrine), and tobacco (Nicotiana rustica)surely would have been present in the Basin by this time, perhaps associated with snuff trays…"(Hastorf 2005: 75). An increase in long distance exchange is commonly found as part of a complex of features associated with ideological and social power during the Middle Formative in the region, and it appears that existing exchange routes, such as the one along the Western Cordillera connecting Chivay with Qillqatani, were increasingly routed towards the Titicaca Basin regional centers during this time.

Late Formative Period (500 BCE - AD 400)

During the Late Formative, significant social ranking developed and dominated the socio-political landscape in the Lake Titicaca Basin. The complex polities that emerged on either end of Lake Titicaca were distinguished by architecture, stoneworking, and ceramic traditions. A three-tiered site size hierarchy is evident in the Late Formative, and the construction of prominent terraced mounds with sunken courts occurred in a few major sites at this time. The elite ceramics and stoneworking, and the construction of elaborate mounds as a venue for large-scale feasts and human sacrifice at sites like Pukara and early Tiwanaku, can be interpreted as a means of demonstrating the large-scale organization of labor by elites (Stanish 2003: 143).

The patterns of obsidian circulation that emerged at the end of the Middle Formative became very well established in the Late Formative. Excavations at centers in the North Basin have found a reduction in the presence of Alca obsidian in the Titicaca Basin, but the Alca material is still present although it is found in minor quantities at the larger sites as compared with Chivay obsidian. The diversity of obsidian types in the Titicaca Basin samples reported by Burger et al. (2000: 306-308) for this time span is low, as compared with the diversity of types used in the Cusco area, because in the Titicaca Basin it is virtually all Chivay obsidian.

In recent excavation work at Pukara on the central pampa at the base of the Qalasaya, Elizabeth Klarich (2005: 255-256) found that obsidian was generally available and obsidian use was not associated with any intrasite status differences. Probable representations of obsidian points and knives appear in Pukara iconography, and small discs have been found at Pukara and Taraco that were possible ceramic inlays (Burger, et al. 2000: 320-321). The Late Formative Period on the southern end of the Titicaca Basin has small amounts of Chivay obsidian at Chiripa and Kallamarka. InGiesso's (2000: 167-168)review of lithic evidence from several Formative Period sites he found no obsidian use in these collections except for samples from Khonkho Wankane which recent research directed by John Janusek has revealed to be principally a Late Formative center. The furthest confirmed examples of transport of Chivay obsidian are these examples encountered in southern Titicaca Basin sites. The two furthest confirmed contexts for Chivay obsidian transport are represented bytwo samples from a Late Formative context at Kallamarka (Burger, et al. 2000: 308, 319, 323) and six samples found at Khonkho Wankane (Giesso 2000: 346), both about 325 km from the Chivay source, or 72 hours by the walking model.

At Qillqatani, the obsidian returns to being primarily Chivay type during the Late Formative although 1 out of the 9 obsidian artifacts analyzed from Late Formative levels was of the Tumuku type (SectionX3.4.2X). During the Late Formative there is a steady decline in the percentage of debitage made from obsidian at Qillqatani, a trend that continues in the Tiwanaku period.

In the Colca Valley, there are few traces of the Late Formative consumers of Chivay obsidian. As will be further explored in this research project, there is very little Qaluyu or Pukara material diagnostic to the Middle or Late Formative in the Chivay obsidian source region. Steven Wernke found a diagnostic classic Pukara sherd with a post-fire incised zoomorphic motif that resembles a camelid-foot from a Formative site above the town of Yanque in the Colca (Wernke 2003: 137-138).

Pukara materials are known to have circulated, probably through trade links, throughout the south-central Andes. Pukara sherds have been found in the valley of Arequipa in association with the local Formative Socabaya ceramics (Cardona Rosas 2002: 55). In the Moquegua valley, both Chiripa-related and Pukara pottery have been found (Feldman 1989), and a Pukara textile was found in a possible elite grave context in the Ica Valley (Conklin 1983).

Discussion and review of "Early Agropastoralists" obsidian

From the Terminal Archaic through the Formative Periods the circulation and consumption of obsidian expanded dramatically. Chivay and Alca obsidian is found in a wide variety of sites from isolated rock shelters to early regional centers, and it appears in consistent quantities that differ considerably from the intermittent nature of regional obsidian supplies in preceding periods. The increased circulation of obsidian is part of a spectrum of changes that began in the Terminal Archaic, but obsidian distribution patterns are particularly useful because they are quantifiable.

In some ways obsidian appears most closely linked to tasks associated with camelid pastoralism, such as shearing and butchering. However, in the central Andean littoral, Quispisisa obsidian is found in density in "cotton preceramic" and Initial Period (i.e., Terminal Archaic and Early Formative) coastal sites where presumably pastoralism, if present, was a very minor part of the economy. Furthermore, in the south-central Andean highlands obsidian is found in pastoralist rock shelters but also in regional centers, and the small discarded obsidian flakes and small projectile points do not appear to have served as adequate shearing implements due to their size.

Social complexity during first part of the "Early Agropastoralists" period is manifested most prominently along the Pacific littoral. In the coastal context of what is now the Department of Lima, in central Peru, monumental architecture dating back to 3000 BCE is well-established at the site of Aspero, and the transition to yet more monumental preceramic construction at sites slightly inland has been documented in recent research(Haas, et al. 2005;Shady Solis, et al. 2001). The shift inland is argued to be related, among other things, to the increased importance of harnessing labor surpluses through the production of cotton for anchovy nets and textiles, and to competitive monument building between elites. Evidence of exchange with highland and Amazonian groups is apparent in the form of tropical feathers and other non-local prestige goods. While these developments occurred over one thousand km to the north of the Chivay area along the Pacific coast, early complex organization is also reported in northern coastal Chile in the Chinchorro II and III traditions spanning the Late Archaic through the Middle Formative(Rivera 1991). A long history of cotton production for nets and textiles, imported wool textiles, elaborate burial traditions, and long distance exchange with the highlands and the Amazon characterize the later Chinchorro tradition. These regional patterns underscore the wide scope of the changes that occurred during the Early Agropastoralists time. It has been argued that the beginning of social inequality in the highland Andes may have been stimulated indirectly by demand for wool from aggrandizers in coastal societies(Aldenderfer 1999).

Returning to evidence from highland obsidian distributions, the widespread circulation of obsidian during the Terminal Archaic and Formative is perhaps best discussed in the terminology used in the historical model of Nuñez and Dillehay(Dillehay and Nuñez 1988;1995 [1979]). While this adaptationalist model has theoretical limitations, it serves as a useful alternative to evolutionary chiefdom models that assign a paramount role to central-places in exchange, despite the decline of central-place models in geography(Smith 1976: 24). Following the Nuñez and Dillehay model, it is possible that what is occurring in the Terminal Archaic and Early Formative is the emergence of regular exchange pattern between Qillqatani and Chivay that took the form of a caravan trade "axis" along the western Cordillera. This exchange pattern is among the earliest systematic and demonstrable cases of the circulation of diffusive items through largely homogenous altiplano terrain (XFigure 3-4X) in the pattern that has also been described as horizontal complementarity or the "Altiplano mode"(Browman 1981). Subsequently, during the Middle and Late Formative in the Titicaca Basin, former "axis settlements" like Qillqatani, and the Western Cordillera axis more generally, became relatively less important in long distance exchange relationships. Regional centers in the Titicaca Basin like Taraco, Pukara, Chiripa, Khonkho Wankane, early Tiwanaku, and other centers, expanded in influence during this period of peer-polity competition. In these circumstances, the acquisition and ceremonial use of exotic goods appears to have been an important part of the competitive strategies of aggrandizers. Other evidence for Titicaca Basin-based exchange dynamics include the possible production of hoes of Incatunahuiri olivine basalt at Camata around 850-650 BCE that were then transported and used in southern Titicaca Basin sites(Bandy 2005: 96;Frye and Steadman 2001). While the nature of the relationship between emerging elites in Titicaca Basin polities and caravan drivers that provided links between settlements throughout the region is difficult to describe with precision, it appears that interregional articulation became considerably more elaborate by the end of the Early Agropastoralist period.

Tiwanaku and Wari (AD400 - 1100)

Following the Titicaca Basin chronology the Tiwanaku period begins with the emergence of the Tiwanaku state during the time that has been called "Tiwanaku IV" beginning around AD400 (Stanish 2003). This is centuries earlier than the start of the Middle Horizon, as defined by the presence of Wari in Ica. Wari in Ica spans the period from approximately AD 750 - 1000.

Late Intermediate Period (AD1100 - 1476)

Current evidence suggests that following the collapse of the Tiwanaku state, a prolonged drought occurred until AD1200 after which time Aymara chiefdoms emerged in the region referred to as Collasuyu by the Inka. A central question of this time period concerns the extent to which obsidian distributions can reveal whether Tiwanaku period interaction patterns persisted into the LIP in the forms assumed by economic organization and long distance exchange. While the LIP is known as the auca runaor the "time of strife" when fortified hilltop refuges " pukaras"were constructed in abundance in the Titicaca Basin and adjacent territories, the weapons used in these conflicts appear to have primarily been percussion weapons like slings and clubs, and not obsidian tipped-projectiles.

Late Horizon (AD1476-1532)

The expansion of the Inka Empire during the Late Horizon resulted in a restructuring of the long distance movement of goods. The ability of the Inka state to transport stone is vividly demonstrated by the transport of hundreds of andesite ashlars weighing up to 700 kg apiece the 1600 km distance from Cusco to Saraguro, Ecuador (Ogburn 2004;Ogburn 2004). The ability to move people and goods over long distances was an integral part of state apparatus; however, it is evident from obsidian distributions that not all goods were more widely distributed during the Late Horizon.

It appears that if the Inka had a particular demand for a substance it could be acquired from over great distances. The Late Horizon was referred to as the "tin horizon" by Lechtman (1976) due to the lengths that the Inka would go to procure tin for copper production. In the Mantaro Valley, tin was not present in Late Intermediate Period coppers but it was found in all seven copper implements from Late Horizon levels where it made up, on average, 5% of the metal composition (Earle 2001: 311;Owen 2001: Tables 11.1-11.3). This tin is thought to have come from mines in Bolivia or southern Peru, and this exchange was facilitated by the Inka state (Lechtman 1976). Thus tin was transported from southern Peru, perhaps from the vicinity of obsidian rich lands of Arequipa, but apparently little obsidian was transported along those same Inka transportation routes.

Ethnohistoric accounts indicate that during the Late Horizon the control of natural resources sometimes occurred through restricted access to raw material sources in the Andes. Access to tunnels leading to particularly rich gold deposits at Inka gold mining operations were restricted at the tunnel mouths (Burger and Glascock 2002: 364;Sancho de La Hoz 1968 [1534]: ch. XVIII: 332). The deposits of other natural resources, such as obsidian, are distributed across the geological landscape such that directly controlling access would have been difficult or impossible.

Burger et al.(2000: 343-347)report very little Chivay obsidian circulating in contexts that are definitely Late Horizon in date. Small quantities of obsidian were found in Cusco, and these turned out to be entirely of the Alca type except for one notable case of Chivay material at Machu Picchu. In one of the only cases of Chivay obsidian use in the department of Cusco since the Late Formative, several unmodified nodules of Chivay obsidian were identified from a collection of small obsidian pebbles excavated by Hiram Bingham in 1912 at the gateway to Machu Picchu. Burger et al. (2000) note the significance of the unmodified state of these small obsidian pebbles, as the small size of these nodules suggest that it was not the tool-making potential, but rather the natural glass itself that was "suitable in its apparently natural state as an offering or sacred object comparable to quartz crystals"(Burger, et al. 2000: 347;Rowe 1946: 297). This view is consistent with observations about the possible significance of the 'essence' of obsidian as natural glass in Andean cosmology that will be explored in more detailed below.

Discussion and review of "Late Prehispanic" obsidian

Obsidian distributions during the Late Prehispanic period reflect the dramatic changes in economy and ideology imposed by powerful states in the region. In the Tiwanaku and Wari spheres of influence obsidian circulation achieved its largest known extent. Particularly intriguing are the examples of non-local obsidian consumption in close proximity to rival obsidian sources, a phenomenon that occurs twice during the Middle Horizon. Three samples of Chivay obsidian were found close to the Sora Sora obsidian source in western Bolivia in a possibly Tiwanaku context (Burger, et al. 2000: 340), and Quispisisa and Alca obsidian were found at the Wari-influenced site of Achachiwa, only 46 km downstream of the Chivay source, in the lower Colca valley (Brooks 1998: 447). During the LIP this pattern of high mobility and sprawling interregional contact is reversed as regional circulation of obsidian is curtailed and the Chivay regional pattern returns to a distribution confined to the Colca region and the North Titicaca Basin. Finally, during the Inka period, obsidian appears to have had a largely diminished significance, particularly in contrast to other materials that were circulated prodigious distances by the Inka. This discussion of the spatial distributions of prehispanic obsidian will be complemented by a review of the uses and forms that obsidian artifacts assume in the archaeological and ethnohistoric record.

Hafting in the Andes

Archaeological evidence shows that bifacially flaked obsidian implements were hafted in a variety of ways. The majority of the hafting evidence from the Andes comes from coastal sites due to superior preservation. Projectile points were hafted to spears, spear thrower darts, and arrow shafts. Obsidian bifacial tools were also hafted to wood or bone handles for use as knives. Hafting materials varied regionally, but hafting was often accomplished using gum or resin, and hafts supported with cotton string have been found in some coastal sites (Carmichael, et al. 1998: 79).

Evidence of use of obsidian

The artifact types predominantly manufactured from obsidian include projectile points and tools for cutting and shearing tasks. While simple flakes are wide-spread and were probably used abundantly for butchering, scraping, and shearing purposes, the utility of obsidian flakes is frequently discounted when flakes are relegated to the "debitage" or "debris" class. In Andean studies bifacially-flaked instruments are the most commonly analyzed obsidian artifact class in archaeological reports from sites in the Andes.

Obsidian artifacts are sometimes found in association with iconographic representations of dark colored artifacts that are similar in appearance to the very obsidian artifacts found in that context (Burger and Asaro 1977: 15). Such is the case with black-tipped darts and knives depicted on Ocucaje 8 through Nasca 6 ceramics and textiles, and obsidian artifacts found in tombs from those contexts. Building on the discussion in Burger and Asaro (1977: 13-18), examples of obsidian artifacts from the south-central Andes follow.

Table 3-10. Examples of obsidian use in the south-centralAndes (part 1).

Table 3-11. Examples of obsidian use in the south-centralAndes (part 2).

Many of these examples are shown in Appendix C. of this volume. While the diversity of artifact forms was relatively low, it is evident that the visual and fracture properties of obsidian were relevant to the tools that were used from this material. Further north in the Andes, in Ecuador, a greater percentage of obsidian artifacts seems to have filled a primarily decorative role, including abead, an ear spool, and three polished mirrors(Burger, et al. 1994: 246).

The evidence of use lithics may also take the form of cutting and scraping marks on faunal remains, but the lithic material type can rarely be established by these means. The continued use of glass and obsidian in modern contexts for shearing, butchery, and castration suggests that the prehispanic metals such as copper and bronze did not displace obsidian and other lithic materials for utilitarian tasks. Prehispanic metals were used largely for display, although metals were used in some weaponry, such as mace-heads (Lechtman 1984).

Obsidian in warfare

The evidence for obsidian use in conflict in the Andes comes from a variety of archaeological and ethnohistorical sources, but it is primarily in the form of indirect evidence. The data reveal a great expansion in the production of small obsidian projectile points after the onset of a food producing economy. The majority of Late Horizon weapons that the Spanish faced during their invasion appear to have been bola stones and percussion weapons like maces and slings(Cahlander, et al. 1980;Korfmann 1973), as well as padded armor.

Archaeologists working in the south-central Andes vary historically in their assessment of the use of projectiles in the highland region(Giesso 2000: 43). Bennett(1946: 23)asserts that the use of bow and arrow were not important on the altiplano, Metraux(1946: 244-245)says that spear throwers were in use, while Kidder(1956: 138)indicates that evidence from projectiles show that arrows were widely used at Tiwanaku. Of the projectile points analyzed by Giesso from Tiwanaku, 19% were made from obsidian, with the highest concentration of points coming from excavations in the civic/ceremonial core at the Akapana East, K'karaña, and Mollo Kontu mounds(Giesso 2000: 228-238).

In a dramatic example of obsidian use as a weapon, one archaeological findError! Reference source not found.shows a probable spear or dart point penetrated the victim's abdomen from the left anterior abdomen and lodged on the anterior side of the lumbar vertebra.

Evidence of use of the bow and arrow in warfare

One of the strongest patterns in obsidian distributions in the south-central Andes is the sudden onset of obsidian use with series 5 projectile points in the Terminal Archaic, after 3300 cal BCE In defining the small type 5D projectile points Klink and Aldenderfer(2005: 54)suggest that the widespread adoption of these point types may reflect the use of bow and arrow technology, as these points fallwithin the size range described by Shott (1997: Table 2) as associated with arrow points (although with substantial overlap with the size of the smaller dart points).

Figure 3-14. Type 5d projectile points from a Terminal Archaic level at Asana and Early Formative levels at Qillqatani, from illustration in Klink and Aldenderfer (2005: 49).

Additional metrics for differentiating arrowheads from dart and spear points have been suggested by Thomas (1978: 470) and Patterson (1985). With Mesoamerican projectile points, Aoyama (2005: 297) has found a very significant correlation between evidence from microwear analysis and projectile dimensions in his effort to differentiate arrowheads from dart and spear points. The relationship between the mass of the item and the velocity and distance of the projectile are discussed in detail by Hughes (1998). She notes that the innovation of fletching allowed for balanced projectiles that had smaller projectile tips and lighter shaft materials, which in turn permitted greater distance and velocity in weapons systems (Hughes 1998). On a related point, the notched base in all type 5 projectile styles reflects a change in hafting technology. Greater impact loads can be absorbed by mounting projectiles tips with notched bases into slotted hafts (Hughes 1998: 367;Van Buren 1974).

Obsidian has a number of attributes that make it a particularly effective material for projectile point tips, most notably are the predictableconchoidal fracture qualities of obsidian that allow it to be pressure flaked into very small projectile points. The sharpness of freshly knapped obsidian margins is unrivalled, andethnographicallyobsidian is renowned as a brittle material that can fracture on impact, causing the fragments to produce greater bleeding in the victim of an obsidian projectile (Ellis 1997: 47-53). In materials science, obsidian has extremely low compression strength because it has no crystalline structure (Hughes 1998: 372). Due to the brittleness or lack of compression strength, missed shots can result in many broken obsidian projectile tips, and perhaps for this reason obsidian was not the predominant material for projectile point production until after the domestication of camelids when hunting was decreasingly the primary source of meat (as inferred from the ratio of camelid to deer bone in excavated assemblages).

Increased velocity and distance is possible with the use of bow and arrow, and obsidian has greater penetrating power, although lower durability, than other material types. Do these changes suggest a greater use of projectiles for warfare? Greater use of small, fletched projectiles might be expected in contexts where the individual needs (1) increased distance from the target (2) increased velocity, perhaps due to change in prey or to the use of padded armor. The use of obsidian may increase in contexts where one needs (1) a material that can be knapped into small, light projectiles as discussed above, (2) increased penetration with sharper material, (3) decreased concern for durability because in warfare the weapon will perhaps be retrieved by the opponent.

Although empirical evidence for warfare is scarce in the Terminal Archaic in the highlands, a study of 144 Chinchorro individuals from Terminal Archaic contexts in extreme northern Chile found that one third of the adults suffered from anterior cranial fractures that probably resulted from interpersonal violence, and men were three times more likely than women to have these wounds (Standen and Arriaza 2000). These wounds appear to have been caused by percussion weapons like slings, but the coastal evidence for interpersonal violence in this time period is strong. Additional support for the introduction of the bow and arrow in the Terminal Archaic come from the region among Chinchorro burials in coastal Northern Chile. Bows among the Chinchorro grave goods date to circa 3700 - 1100 cal. BCE, or the Terminal Archaic and Early Formative (Bittmann and Munizaga 1979;Rivera 1991;Standen 2003).

Possible use of poisons on projectile tips

A potential explanation of widespread adoption of the small type 5D projectile points is the greater availability of poisons that reduced the need for heavy, destructive projectiles.South American poison arrows are usually quite small and such arrows are frequently tipped only with a sharpened wooden point. According to Ellis(1997: 55),virtually all ethnographic examples of arrow use include some kind of poison applied to the arrow in order to have either a toxic or a septic effect on the victim. Ellis observes that due to the great variety of substances used to create such toxins, in many regions of study these substances would probably contaminate any chemical attempt to use residue analysis to differentiate the types of poisons used, or even the prey that was hunted, with a particular used projectile point.

A variety ofhighly effective poisons are applied to the tips of projectiles by hunters in the Amazon Basin today(Heath and Chiara 1977).In the prehispanic Andean highlands, trade contacts with the Amazonian lowlands to the east may have made available poison concoctionsfor application to projectiles, most notoriously the fast acting paralysis alkaloid curareprepared from the vine Chondrodendron tomentosum(Casarett, et al. 1996).

Bernabé Cobo (1990 [1653]: 216-217) discusses the use of bow and arrow with poisons by "expert marksmen" in his chapter on warfare. Hedescribes the widespread and expert use of the sling for warfare, which is consistent with reports elsewhere on the use of slings, but then he states that bow and arrow were more significant in warfare.

The most widespread weapon of all the Indies, not only in war but also in the hunt, was the bow and arrow. Their bows were made as tall and even taller than a man, and some of them were eight or ten palms long, of a certain black palm called chontawhose wood is very heavy and tough; the cord was made of animal tendons, cabuya, or some other strong material; the arrows, of a light material such as rushes, reeds, or cane, or other sticks just as light, with the tip and point of chontaor some other tough, barbed wood, bone, or animal tooth, obsidian point, or fish spine.

Many used poisoned arrows, their points anointed with a strong poison; but, among the nations of this realm, only the Chunchosused this poisonous herb on their arrows, and it was not a simple herb, but a mixture of various poisonous herbs and vermin; and it was so effective and deadly that anyone hit by one of those poisoned arrows who shed blood, even though it might be no more than the blood resulting from the prick of a needle, died raving and making frightful grimaces(Cobo 1990 [1653]: 216-217).

The Chunchos ethnic group is described as living in the "forests east of Lake Titicaca on the border of the Inca Empire".It is possible that Amazonian poisons became available in altiplano during the Terminal Archaic due to expanding exchange networks, together with Amazonian hallucinogenics and other lowland products, dramatically altering the efficacy of arrows. As a sharp but lightweight weapon, obsidian tipped arrows would have represented an effective poison delivery system to animal and human victims alike.

While there is no direct evidence for the use of Amazonian poisons on the altiplano, the dramatic change in projectile technology with the type 5D type, co-eval with expanding exchange networks in the region, suggest that a new technology for weapons systems, such as poisons and new shaft and fletching materials, may have influenced the design of projectiles in this time.The transitional economic context of the Terminal Archaic involved many changes, including shifts in both food production and interregional exchange, and the technology of lithic production show significant alterations that correspond to this period.

Multiethnic access to geological sources in the Andes

Salt procurement in the Amazon basin on the eastern flanks of the Andes provides an example of multiethnic access to a raw material source. During annual voyages to the Chanchamayo salt quarry ten days outside of their territory, the Asháninka of the Gran Pajonal (Ucayali, Peru) combine salt procurement with exchange with neighboring groups who share access to the source(Varese 2002: 33-35). Arturo Wertheman, a missionary who traveled through the region in 1876, explains

Throughout the year small bands of Asháninka traders traveled [the Gran Pajonal] paths to obtain salt, carrying with them tunics or ceramics to exchange for other items and for hospitality. With them traveled their traditions, their hopes, and the information of interest to their society. The Pajonal, the vast center of Campa territory not yet invaded by whites, appears to have been the center of culture and tradition through which the Indians journeyed, like a constant flow of life through their very society(Varese 2002: 120)

Other ethnographic examples of multiethnic access to salt quarries are mentioned in the ethnographic literature. Oberem(1985 [1974]: 353-354)describes access by both the Quijo and the Canelo people to a large rock salt quarry located on the Huallaga River, a tributary to the Amazon lying further north on the border of Peru and Ecuador.

In the Cotahuasi valley of Arequipa, to the north of the Colca valley, the rock salt mine of Warwa [Huarhua] has been exploited since Archaic times(Jennings 2002: 217-218, 247-251, 564-566). Access to the Warwa quarry, which lies near the border of the departments of Arequipa, Ayacucho, and Apurímac, is described by Concha Contreras(1975: 74-76)as including caravan drivers from all three of those neighboring departments.

El primer viaje lo hacen, mayormente, en el mes de abril. En esta época cientos de pastores se concentran en esta mina. El camino es estrecho y accidentado hasta llegar a la misma bocamina…Desde el fondo de la mina los pastores cargan a la espalda la cantidad de sal que necesitan llevar, de tal manera que hacen muchos viajes al socavón de la mina. En todo este tramo tardan 4 días, porque después de la mina, siguen cargando en la espalda hasta una distancia de aproximadamente cinco kilómetros, donde quedaron las llamas pastando, puesto que hasta la misma mina no pueden entrar juntamente con sus llamas(Concha Contreras 1975: 74).

There appear to be a number of protocols associated with salt acquisition at Warwa. Notably, the multiethnic visits by caravanners from various departments coincide in April despite the tight working quarters at the salt mine. Furthermore, there seems to be concern for impacts in the much-visited the mine area itself. The cargo animals are actually grazing a distance from the quarry and humans are obliged to carry the loads to these areas instead of attempting to load the animals close to the mine. These cases of multiethnic raw material access provide examples of the social and institutional nature of access to unique geological sources, and the focalized attention that these source receive from surrounding ethnic groups. The analogy with regional acquisition and diffusive transport of the raw material is perhaps the closest modern analogy to the nature of prehispanic obsidian quarrying that remains in the Andes.

How did the social and symbolic importance of obsidian change through time and space?

Obsidian flakes and bifacial tools were sometimes included as grave goods from the Terminal Archaic (3300 cal BCE) and onwards. Ethnohistoric accounts and archaeological evidence indicate that obsidian "knives" were employed in ritual practice as well as in medical procedures throughout the region, although it is not evident if these were bifacially-flaked tools or simply freshly struck flakes. In addition, concentrations of flakes of quartz as well as obsidian from a variety of non-local sources were found in the Tiwanaku ceremonial mound of Mollo Kontu in a regular pattern that was interpreted by Couture (2003) to indicate deliberate inclusion in clay fill rather than accidental redeposition.

Based on analogy from other goods, it is possible that in areas where obsidian is used in ceremonial contexts a finely-made obsidian implement may have been less likely to have been exchanged as an alienable product traded in barter. In some historical contexts, a ritual item may become a singular item and acquire a distinctive 'genealogy' related to its social history that precludes it from being bartered and circulated in equivalence for something ordinary such as a sack of potatoes (Hodder 1982;Kopytoff 1986).

However, on the whole, obsidian appears to be one of a number of products that escapes easy classification. On one hand, obsidian circulated in established networks controlled by llama caravan drivers who were responsible for the distribution of a variety of goods on the altiplano. These caravans appear to have been organized by households and derived communities of relatively humble means, to judge from other aspects of their material lives excavated at sites like Qillqatani. On the other hand, as a luminescent material with irregular spatial availability, obsidian had properties that qualify it as a "prestige good" in many contexts (Hayden 1998). In terms of rituals organized and performed on a local level, obsidian was probably one of a number of materials that were traditional but non-the-less slightly rare like ochre and shell. Craig (2005: 683-693) explores the evidence for the symbolic importance of discrete color groups in ritual items like ochre and obsidian in the Titicaca Basin Archaic and Formative site of Jiskairumoko by examining the patterning of obsidian and ochre in comparison to what were common-place, functional applications of these goods.

From the perspective of early aggrandizers in the Terminal Archaic and Formative Lake Titicaca Basin, obsidian probably represented a somewhat elusive product for labor investment and therefore was not a principal substance used in elite strategies by the time of the Middle and Late Formative. From the perspective of prestige technologies serving the agenda of aggrandizers by locking up surplus labor (Hayden 1998), the issue might be considered in terms of the following factors:

(1) Obsidian was relatively easy to acquire, perhaps too easily acquired, for the people living in the highlands of Arequipa; and it was not concentrated in specific, controllable points accessed only through mine shafts.

(2) Obsidian has functional properties that assured its continued circulation for the production of cutting and piercing implements, making it insufficiently rare to have served as a "preciosity" (Clark and Blake 1994;Goldstein 2000).

(3) While craft specialization was fostered in more closely-controllable contexts in regional centers during the Formative, obsidian sources were perhaps sufficiently distant to have escaped this kind of specialized craft production. In contrast, consider the various non-utilitarian obsidian products made by craftspeople in Mesoamerica, discussed above.

(4) As obsidian was primarily made into projectile point tips, it was perhaps associated with hunting, or the threat of violence. In some regional traditions, such as in Nasca iconography, obsidian appears to have been associated with trophy head taking. However, in the south-central Andean highlands there is no evidence of a direct association between violence, emerging leadership, and control of surpluses along the lines of Hayden's (1995) despotic leader model.

Obsidian products, particularly finely-made bifacial tools, were perhaps one of a series of items that served to differentiate status-seeking individuals in early transegalitarian contexts, but with later crafts investment obsidian appears to have been assigned a relatively specific role for projectile point production and for cutting implements.

Do changes in use of obsidian reflect local geographic availability?

One way to examine the social and symbolic significance of obsidian is to examine the changing use of the material as availability declines with distance from the geological source. To judge from the distant consumption zone, obsidian was used in both mundane contexts and also in ritual or ceremonial contexts. At Tiwanaku, obsidian was found dispersed into the fill of ceremonial mounds (Couture 2003). It is also sometimes found in Titicaca Basin burials as of the Terminal Archaic. As reported by Craig (2005: 570-574, 679-682), at Jiskairumoko and at other sites in the Ilave valley, obsidian has been found in burials dating to 3300 cal BCE and later along with other non-local goods including lapis lazuli (sodalite) beads, gold discs, and gold beads, as well as ritual items like a camelid effigy made from bone. If the associations of obsidian with ritual power were related to its non-local origins, one might expect this pattern to have been weaker in closer proximity to the Chivay source. Items from ritual contexts, such as grave goods from the Colca Valley, and in close proximity to the Chivay obsidian source, may provide data to test this hypothesis.

Do the unusual visual qualities of obsidian resonate with Andean traditions?

Andean traditions place a priority on visual attributes, and links between the visual purity of a material and its essence have been widely noted in some segments of the Andean literature. As a natural glass, the aqueous properties of obsidian cause the material to reflect light which may display the workmanship of obsidian artifacts, as well as the potential sharpness of obsidian tools. Obsidian used for prehistoric tool production was often a homogeneous glass that was visibly consistent, pure in color, and sometimes transparent or banded. The importance of visual qualities of metals in the Andes has received greater attention:

The social arena in which metallurgy received its greatest stimulus in the Andes was the arena dominated by status and political display. An underlying cultural value system that appears to have strongly influenced the visual manifestation of status and power was a color symbolism oriented around the colors of silver and of gold. The most innovative and interesting aspects of Andean metallurgy arose from attempts by Andean metalsmiths to produce metallic gold and metallic silver surfaces on metal objects that were made of neither metal (Lechtman 1984: 15).

In Andean metallurgy, the appearance of consistency in color, reflectivity and material was prioritized because visual characteristics conveyed information about the inherent essence and animation of the object (Lechtman 1984: 33-36).

There is little direct support in Andean archaeological or ethnohistorical sources for inference regarding how obsidian was perceived, but it would be consistent for obsidian, a stone with the appearance of watery luster, to be associated with ceremonial power and ritual sacrifice given the well-demonstrated importance of stone and water in Andean cosmology.

Were the visual differences between obsidian types in the Andes important?

Visible differences between obsidian chemical types in the region are principally in terms of nodule size, fracture characteristics, glass color, and cortex. While nodule size and fracture characteristics are believed to have been important determining factors in explaining which obsidian types were circulated widely in prehistory (Burger, et al. 2000: 348), glass color is more of visual aesthetic issue. The obsidian sources in the south-central Andes are predominantly black or grey. Obsidian from the Chivay source is often a transparent grey and banded, and Quispisisa obsidian sometimes has a red coloration, although Burger et al. (2000: 314) state that the Quispisisa type is visually indistinguishable from Alca obsidian. As with many goods with discrete places of origin, these visual differences communicate information about the spatial origin of the stone that would have visually linked the material with regions and socio-political groups to knowledgeable viewers. To Brooks (1998: 452;1997) the transparency of Chivay obsidian was a reason for its wide circulation in prehistory. Others have commented on the transparency of the material including Giesso (2000;2003), and Burger et al (2000: 296). Giesso (2003: 368) observes that archaeological and ethnographic evidence from the Andes indicate that "transparent elements were viewed as mediators between different cosmological worlds". Further study may permit evaluation of observed patterns in the contexts of obsidian use that are linked to color.

Discussion

The social and ritual significance of obsidian in particular prehispanic Andean contexts appears to have varied across time and space, and with further research in the region into evidence of production and consumption these differences will be better understood. Archaeologists have established that the visual attributes of particular materials like metal were important in the late Prehispanic Andes. If this mode of interpretation may be extended, high quality obsidian shares some visual characteristics with metal such as shininess and an appearance of material purity. Furthermore, obsidian from particular areas was often visually distinct and this may have conveyed information in regions such as Moquegua where a variety of obsidian types have been encountered. Obsidian was irregularly available across the landscape, and the mere possession of this highly visible material in obsidian-poor regions had possible social significance because it suggested that the holder participated in long distance exchange networks or had alliances with groups in obsidian-rich areas.

Description

Direct acquisition by the end user entails high mobility and multiethnic access to the Chivay source. In this model, those traveling to the source would procure only sufficient obsidian for their household or community needs and no more. The evidence of procurement at the source would be the direct impacts of communities of consumers where obsidian was perhaps circulated in a context of generalized reciprocity but specifically not exchanged against goods in truequebarter, as that is a different type of procurement. Thus, this category consists of direct, personal visits by the immediate consuming household throughout prehistory.

Table 3-12. Models of procurement and exchange for Chivay obsidian. Compare terms with those used in Figure 2-2 and Figure 3-3.

Based on low population densities during the Early Holocene it is assumed that the earliest regional consumers of Chivay obsidian in the south-central Andes, the residents of Asana circa 9400 BP, acquired obsidian directly. Direct household acquisition of resources, such as salt procurement, persists to this day in a few places in the Andean highlands. It is possible that the multi-ethnic nature of access to Andean salt mines may serve as a model for procurement that occurred at Chivay during much of prehistory.

As it is generally the altiplano pastoralists that possess the major means of transport, llama pack animals, and direct household procurement by such groups was perhaps common for many types of goods. For example, herders from the community of Paratía (Flores Ochoa 1968: 87-109), to the north-west of Juliaca in the department of Puno, made regular trips to the Colca valley to acquire agricultural goods. If Paratíans traveled directly, it is likely that they used the Quebrada Escalera route passing to the north of Nevado Huarancante which would pass only a few kilometers from the Maymeja area of the Chivay source. On the return voyage from the Colca, if llamas were not overly burdened, a special stop could have been made to acquire a few nodules of obsidian. Similarly, the household-organized llama caravans described by Nielsen (2001) could well have obtained lithic raw material for household consumption if their travel route passed adjacent to a scarce raw material source on a return journey.

This mode of transport requires that consuming households had the social and physical means to travel to the obsidian source. The ability to partake in regional transport, even in a logistical fashion described by Flores Ochoa and by Nielsen, required strong animals, the food security to undergo a risky journey, peaceful conditions and personal security on the isolated travel routes, probable social relationships or contracts with communities encountered along the way, and knowledge of the extraction source area. Conditions of multiethnic access were likely variable in prehistory and knowledge of travel routes and sources of raw material were best obtained through cordial relations with local groups. In short, this means of obsidian distribution requires relatively cosmopolitan travelers with the resources to personally visit the sources of goods needed by the household. This mode of transport is relatively inefficient because individual households or communities sharing resources, by definition, have to personally acquire and produce obsidian in this model of obsidian procurement.

Material Expectations

In the immediate vicinity of the obsidian source archaeological evidence of the direct acquisition mode would produce high variability in procurement, but relatively small quantities in production because consumption would be limited to the households of those visiting the source. Greater amounts of advanced reduction evidence, including bifacial thinning flakes and tools, broken and discarded during manufacture, will be in evidence at the source area. This type of procurement would have the greatest chance of resulting in diagnostic projectile points in the area as advanced reduction and potential discard in the area of the source is expected. When temporal control is available, primarily from datable organic material in excavated contexts, direct acquisition should result in irregular visits to the source area based on household need. In excavation units cultural material will likely be low-density, as soil and perhaps ash from adjacent active volcanoes will have time to accumulate as visitation rates are low.

There is some chance that undecorated, non-local pottery might be found in association with quarrying or with adjacent rest area bofedal zones. For example, Formative Period ceramics from the southern Lake Titicaca are typically fiber tempered, but in the north basin and in the Colca they are grit tempered. Evidence of fiber tempered plainware may have resulted from discard during direct access procurement by southern Titicaca Basin visitors. Other temper and paste characteristics may serve to identify non-local pottery. Alternately, non-local pottery may result from reciprocation activities (i.e., the Down-the-line model), but the notion here is that non-decorated, utilitarian pottery may have been too crude to have served as barter goods.

Description

The multiple reciprocal exchanges model involves the direct acquisition of obsidian by local people for the express purpose of transferring the obsidian to neighboring communities in exchange for other items. In this model, people residing in Chivay area, perhaps no more than one day's travel from the source, procure material and transport it to a location where the obsidian is then exchanged with neighbors.

This kind of procurement resembles Renfrew's (1975: 520) "Reciprocity" and the "Down-the-line" modes (see Figure 2-2), where goods are exchanged with neighboring groups of roughly equal status through a variety of configurations that are essentially reciprocal in some form. While a synchronic barter of obsidian for, say, a chunk of ochre from the neighboring region is easiest to describe conceptually, reciprocity relationships are a manifestation of a wide range of social mechanisms (Section 2.2.2). In the context of the Chivay area, reciprocal exchange arrangements such as barter for other products, or for grazing rights, for labor, or for social functions such as bridewealth, may be evident. Furthermore, delayed reciprocal arrangements between neighbors are extremely common. Evidence of Down-the-line exchange may be encountered in a wide variety of socio-political contexts from Archaic Foragers to agro-pastoralists living on the periphery of states during the Late Prehispanic. If demand for a product is sufficiently high, archaeological evidence may be encountered of individuals devoting themselves to procurement in order to satisfy regional demand, but substantial quantities of goods would have to be reciprocated because the households that are sponsoring this increased procurement would have fewer provisioners working to bring subsistence to the household. Thus, if down-the-line demand is sufficiently great then the households devoting themselves to elevated rates of procurement would need to barter products for subsistence goods. In the Andes, the pattern observed from items like salt (Concha Contreras 1975: 74-76;Nielsen 2000) suggests that in modern circumstances when demand, and barter values, are sufficiently high, then the down-the-line network may be simply by-passed in favor of procurement through personal or caravan acquisition. Caravans from the consuming zone or adjacent highland areas will make the journey to procure the material and transport it for household use and for barter (a combination of the Direct Access model and the Independent Caravans model).

In a functioning Down-the-line system the flow of information is also important. The changes in the regional demand for a product like obsidian can return to the source area procurers through direct requests, or it might be reflected in increased barter value in a market context. Information exchange may also return specific demands from consumers as to the size, form, or quality of the source material. The temporal regularity of down-the-line reciprocal trade may also be quite variable, as down-the-line networks may dwindle and then be revived during a seasonal gathering or ceremonial occasion. Reciprocal relationships can take the form of mutualism and buffering, they may result from a need to complement the resources on a neighbor's territory, and they often present opportunities for ambitious individuals to advance their interests through differential access to non-local goods.

Material Expectations

Down-the-line procurement involves local people visiting the Chivay source and acquiring goods to supply the reciprocal exchange network, however large that it may be. In the quarry area one should expect local visitors, and therefore local styles in both discarded materials and local architecture. Procurement may take place in the context of embedded economic activities, such as hunting forays into the high country or pasturing of camelids in the rich bofedal adjacent to the source.

If reciprocation for obsidian takes the form of portable objects, such as non-local ceramics, one may encounter diagnostic, non-local goods in the communities adjacent to the obsidian source. These may be in the form of styles belonging to neighboring communities, or more exotic styles may be found on non-local goods that could have arrived through the exchange network from even more distant areas. There is a high likelihood that reciprocation for obsidian would have taken place in other forms as well: goods that are perishable, labor, or other assets that are otherwise less easy to detect.

If locals are involved obsidian procurement at the Chivay source one may also find that the large nodules available at the Chivay source are used in the local economy as well. That is, if nodules in the Chivay source are up to 30cm in length then large flakes, either cortical or non-cortical, may be expected to have been discarded in residential contexts in local communities. If large nodules are available then those that are not exchanged with reciprocal partners are put to use for local needs. Thus when large cores and flakes are procured in the Chivay source area, then appropriately large flakes should be discarded in the middens of communities in the adjacent consumption zone in the upper Colca.

Procurement and initial reduction at the source will have relatively low variability because it is conducted by the same local methods. Local people will have better knowledge of high quality extraction loci and perhaps there is lower variability in procurement locations as a result. As reciprocity networks, and particularly barter arrangements, are contingent on visual attributes of bartered items one should expect medium reduction of material at the source or in the adjacent communities. At the very least, nodules will be partially decorticated and an initial strike that provides entry into the core should be expected, as this serves to expose the quality of material on the interior to barter partners. Furthermore, if transport does not involve camelid cargo animals (because reciprocity is either taking place pre-domestication during the Archaic Forager period, or otherwise does not involve camelids) one might expect a greater concern for the weight of the nodules and therefore further reduction in the vicinity of the obsidian source.

More advanced reduction may also be expected as it minimizes risk and waste by producing blanks, preforms, and prepared cores in the vicinity of the source where obsidian is abundant. However, according to the Down-the-line model producers have the greatest social distance, and therefore the least information, about their consumers. Advanced reduction limits the possible forms that artifacts may take, and therefore producers would need to know what kinds of tools consumers were planning to produce in order to move beyond initial stages of reduction. Thus medium level reduction might be expected, but not an abundance of advanced reduction at the Chivay obsidian source.

Description

Long distance transport of goods by way of camelid caravans was well established in the prehispanic Andes. The strongest evidence for the importance of caravan transport comes in the form of ethnohistoric and ethnoarchaeological studies described earlier in this chapter, however archaeological evidence of caravan traffic is usually very light and it often requires inference from indirect evidence. The "Independent Caravans Model" described here consists of caravans organized on the household level, although ethnographic studies show that, in practice, the members of several households will often band together for company and for safety while participating in long distance caravans. It is worth pointing out that independent long distance transport does not necessarily involve cargo animals. It is possible that small quantities of obsidian were carried bytraveling peddlers. As a variant to this model, one should consider that peddlers carrying small portable items, mostly cultural goods like herbs, shell, feathers, but potentially small obsidian tools or cores, could have circulated objects widely without the assistance of llamas.

According to this model, a household with a sufficient number of cargo animals, usually castrated male llamas, will initiate a trade caravan by transporting goods that they expect will be in demand, to regions that they anticipate will have complementary goods to offer them. According to some descriptions, caravans are pursuing a directed acquisition of specific goods and then they return directly home, while other models describe entire circuits where herders acquire goods, travel, barter for other goods, travel some more, perhaps re-trade their new goods and so on; finally returning to their place of origin several months later.

The mere presence of products distributed over larger distances is not proof of caravan transport, either household organized or administered, because other modes such as direct acquisition and down-the-line models actually result in widely dispersed goods as well. Furthermore, many of the distinctive objects that archaeologists recognize as non-local are often small enough to have been transported without cargo animals. Establishing the beginnings of caravan transport is not a simple task because there is no one signature for long distance caravan organization that is distinctive from other modes of transport. Furthermore, many of the goods are believed to have been perishable, complicating efforts to interpret prehispanic trade caravan patterns. Finally, studies of contemporary caravans emphasize that diversified strategies characterize caravan driving, whether in making daily decisions while on the trail, or in the larger context of economy and exchange. It is thus difficult to define a consistent indicator for caravan activity.

Portable diagnostic artifacts, whether decorated ceramics or other exotic goods, are often relatively small and therefore the artifact weight and total quantity frequently cannot be used to differentiate between caravan transport, traveling peddlers, and down-the-line exchange. The temporal regularity of exchange, however, is a consistent measure that archaeologists can recover from stratified deposits. When regular caravan transport routes developed then the scheduling of such transport may have been linked to the timing of annual events such as harvests and annual ceremonies, and if so these cyclical patterns would result a steady accumulation of non-local goods through time. In contrast, down-the-line exchange depends upon the articulation of many individual exchanges and it is not linked to the acquisition of scheduled harvest products in the same manner as caravan transport and therefore the presence non-local goods would have been irregular.

In terms of the network configurations discussed earlier (Figure 2-3), the configuration that describes the diffusion of obsidian in the region is distinct from the configuration of the regular articulation between herders and farmers that involved the barter of pastoral products for agricultural products. However the regular conveyance of some agricultural goods adjacent to a raw material source creates a context for conveying larger quantities of obsidian regionally. Ethnographic studies indicate that caravans will opportunistically embed exchange into other activities. For example, Nielsen (2000: 488) explains that caravans primarily organized around salt transport would carry a variety of other trade items, and they would occasionally stop to procure raw materials, such as lithics, when the caravan route travels past a known source. Similarly, there is caravans that visited the Colca valley in prehistory from the Titicaca Basin were passing with 3 km of the Chivay source if they used one of the popular routes into the Colca from the south-east direction. Thus, procurement of obsidian was likely to have been associated with long distance exchange opportunities.

Material Expectations

Caravan procurement would have consisted of pastoralists traveling to the Chivay source, acquiring obsidian that they believed to have exchange value, perhaps processing the nodules to some extent, and then transporting the material to consumers or to other traders in areas far from Colca. As temporality is a significant part of caravan organization, regular and dense procurement activities are expected when a caravan undertakes a detour from the principal travel route. Some preparation or maintenance of the trail from the principal travel route to the obsidian source is expected if the animals are heavily laden. The amount of processing and initial reduction in the source area probably reflected the number of days that a caravan would have been willing stop, and conversely the transport of whole nodules is conceivable with the assistance of cargo animals such that some extra grams of weight were less of a limiting factor. As mentioned, cortex is often very thin on Chivay obsidian, therefore it would not be surprising if some percentage of the material transported away from the source area included unreduced, whole nodules.

Ethnoarchaeological studies report that caravan drivers look for camps that include high quality pasture, water, and corrals if possible. When these features occur close to an extraction site, a relatively dense obsidian processing area may be found nearby because herders can nourish their livestock while simultaneously working stone. Because of the temporality of caravan activity, procurement was probably intensive, though episodic, through time. When caravans or animals were present, processing would occur and then the material would be conveyed away and the quarry area would see little use until the next episode of intense production. Evidence of production may be variable, however, because caravans could also transport whole nodules without very much difficulty.

Many of the artifact types that were produced from obsidian transported by caravans can deduced based on archaeological evidence acquired from consumption contexts dating to the Terminal Archaic and later. The principal artifact form made from obsidian during the time that camelid caravans conceivably operated (subsequent to the Late Archaic), is the small triangular projectile point diagnostic to the Terminal Archaic and later. This is not to say that other tool forms were not being made, as other non-diagnostic biface forms could also date to the Terminal Archaic or later, however the vast majority of bifacially-flaked obsidian artifacts are projectile points. Furthermore, cores were likely transported away from the obsidian source because simple flakes serve as valuable cutting tools. Therefore, the majority of obsidian production would have prioritized the production of cores and flakes that serve as blanks for triangular point production. If advanced reduction occurred in the quarry area it is likely that small, triangular point forms were the objective.

Reduction strategies that target the production of small triangular points were probably relatively flexible because these point forms are not especially long or delicate, and therefore it would have been possible to produce the appropriate blanks from a variety of core forms. None-the-less, the overall variability in formal tools forms produced from obsidian is exceptionally low because series 5 points look quite similar. Therefore in terms of intensified production from the Terminal Archaic and onward, relatively consistent reduction strategies in the procurement workshop zone may be encountered.

Because these caravans were independent, one might expect slightly greater variability than in the other models of obsidian distribution because various individual households were participating in this procurement, and methodological variation by region might be reflected in the reduction methods. Finally, independent caravans may behave in other, relatively variable ways such as in architecture, in divergent ceramic styles, and in the types of obsidian pieces that were being exported.

Description

Ethnohistoric evidence suggests that elites commissioned long distance trade caravans to procure materials that were used in a variety of elite strategies at the regional center. As discussed above, Stanish argues that Titicaca Basin elite-administered long distance trade involved acquiring goods for favorable barter rates in distant valleys and then acquiring prestige from the redistribution of these goods. Late Prehispanic elites were probably in a good position to initiate large caravans: they had immense camelid herds and their followers owned them tax payments in the form of labor. In addition, elites would have had the surpluses necessary to initiate a large scale trading venture.

Would such caravans have visited the Chivay source and extracted obsidian for elite consumption or redistribution? Stanish (2003: 69) argues that all Prehispanic trade was administered trade, as opposed to market-driven trade, but he specifically excludes trade in obsidian as "small and light" and capable of being transported through down-the-line exchange. Obsidian does not appear to have been a high prestige item along the lines of precious metals in the prehispanic Andes. Under the Inka there is evidence of control of access to tunnels leading to rich gold mines in the Andes (Burger and Glascock 2002: 364). With obsidian, however, there is no evidence of elite control either in obsidian consumption patterns in regional centers, or in the Arequipa obsidian quarry areas that are generally dispersed and it would have proved difficult to limit access to them (Jennings and Glascock 2002: 115-116). Thus extensive elite-administered acquisition or redistribution of obsidian should not be expected. Nevertheless, given the importance of exchange and non-local goods in issues relating to the origins of social complexity, any evidence of elite-organized raw material procurement should be studied closely.

Material Expectations

Elite-administered caravans would be relatively difficult to differentiate from independent caravans in their source activities. Elite related diagnostic pottery may be encountered in the vicinity of the source area. There may have been some degree of greater standardization if these were part time or full-time specialists working for the elites. Elite-sponsored procurement may involve greater intensification than would be expected from independent caravan procurement because these task groups likely have been organized and dedicated to the procurement objective. Finally, the export of large nodules may have increased as elite-sponsored caravan trains were reportedly large and capable, and the weight of nodules would not have overly interfered with the progress of the caravan following this model. In addition, if the object of elites was prestige building, larger nodules would probably have been more impressive in the distant consumption zone. In short, differentiating elite sponsored caravans at the source may be relatively difficult unless pottery or some other diagnostic material is found to have been associated with procurement.