Chivay obsidian in the Early Archaic

Evidence of human use of the Chivay Source beginning in the Early Archaic Period comes from survey work adjacent to the source and from excavations at the site of Asana, 200 km away in Moquegua. As will be discussed in Chapter 7, during the course of survey work in the area of the Chivay source in 2003 the Upper Colca team collected several dozen Early Archaic type projectile points, the majority of them made from obsidian. Evidence for the regional consumption of Chivay obsidian begins with the site ofXAsanaXthat were described earlier in SectionX3.4.1XandXTable 3-4X. Aldenderfer(1998: 157, 163;2000: 383-384)encountered small quantities of obsidian in two levels belonging to the Asana II/Khituña Phase, placing them in the Early Archaic Period. In level PXXIX just one obsidian flake from Chivay was identified in an assemblage consisting of 1,152 lithic artifacts weighing 746 g. This level could not be dated directly, but it is assessed at 9400 uncal bp as it lies stratigraphically above a¹⁴C sample from level XXXIII dating to 9820±150¹⁴C yr bp (Beta-40063; 10,000-8700 BCE).

Obsidian from Chivay appeared in greater quantity in level PXXIV where eleven flakes of Chivay obsidian made up 0.36% of the lithic assemblage by count. These flakes were all small tertariary flakes, chunks, and shatter, suggesting to Aldenderfer(1998: 163)that a bifacial core of Chivay material was reduced on site. A¹⁴C sample from level PXXIV dated to 8720±120 bp (Beta-35599; 8250-7550 BCE). The Khituña phase has been interpreted by Aldenderfer(1998: 172-173)as representing a residential base in the high sierra and the beginnings of permanent settlement above 2500m in elevation. This interpretation is based on the presence of high sierra and puna lithic raw materials, but no coastal materials.

In surface contexts in the Ilave valley, surveys directed by Aldenderfer(1997)located three obsidian projectile points in forms that are possibly diagnostic to the Early and Early-Middle Archaic transitional period (types 1A, 3A, 3B). These three points were analyzed using a portable XRF unit in 2005 and all three were found to be of the Chivay type(Craig and Aldenderfer In Press).

Alca obsidian at Quebrada Jaguay

The earliest obsidian identified in the south-central Andes comes from one of the oldest confirmed sites in South America, the Paleo-Indian site of Quebrada Jaguay 280 near the coast north of Camaná, Arequipa. Sandweiss et al.(1998)report that Alca type obsidian was the dominant lithic material at the site in the Terminal Pleistocene and Early Holocene phases that were identified. Twenty-six Alca type obsidian flakes came from the older occupation that occurred during the Terminal Pleistocene and the context is dated by twelve¹⁴C dates on charcoal falling between 11,105±260 bp (BGS-1942; 11,700-10,400 BCE) and 9850±170 bp (BGS-1956; 10,100-8700 BCE). A later occupation contained one flake of Alca obsidian and it belonged to the Early Holocene II phase dated by four¹⁴C samples falling between 8053±115 (BGS-1944; 7350-6650 BCE) and 7500±130 (BGS-1700; 6600-6050 BCE). Three other obsidian flakes from the Alca source were collected but they could not be assigned to a temporal context.

Sandweiss et al. observe that the Chivay source is "less than 20 km further; the absence of Chivay obsidian at QJ-280 may indicate that this source was covered by glacial readvance during the Younger Dryas (circa 11,000 to 10,000¹⁴C yr B.P.)"(Sandweiss, et al. 1998: 1832). The Maymeja volcanic depression of the Chivay obsidian source indeed shows notable evidence of recent glaciation, but obsidian matching the "Chivay Type" is also found in smaller nodules on adjacent slopes outside the Maymeja zone as well as in the streambed below Maymeja having eroded through alluvial erosion (see Section4.5.1for maps and a discussion of the Chivay obsidian source geography). Procurement of obsidian from Chivay did not necessarily require entering the Maymeja area, however better source material can be obtained from the within the area.

Regional scale GIS analyses show Quebrada Jaguay to be 154 linear km from the Alca source, or 35.7 hours by the hiking function. In contrast, the trip to Quebrada Jaguay from the Chivay source is 170 linear km and 41.5 hours by the hiking function. Despite this relatively difference in distance, no Chivay obsidian was found at Quebrada Jaguay. It is worth noting that, despite this early find of Alca obsidian on coast, both the Alca and the Chivayobsidian types were predominantly found at high altitude throughout prehistory based on current evidence from obsidian sourcing studies. In the bigger picture, the coastal Quebrada Jaguay paleoindian finds are anomalous for Alca distributions. The next lowest altitude context for Alca to date is at the site of Omo in Moquegua, a Tiwanaku colony site at 1250 masl dating to the Middle Horizon.

Recent work by Kurt Rademaker and colleagues at the Alca source has shown that bedrock outcrops of obsidian are found as high as 4800 masl, and there are large pieces found at 3,800 masl that appear to have been transported downslope by glacial action and colluviation (K. Rademaker 2005, pers. comm.). Deposits of Alca obsidian at much lower elevations have been reported that are probably the result of pyroclastic flows(Burger, et al. 1998;Jennings and Glascock 2002). These deposits found close to the floor of the Cotahuasi valley at 2500 masl were probably available throughout the Younger Dryas and perhaps further sub-sourcing of Alca obsidian will better answer the question of which Alca deposits were being consumed during the Terminal Pleistocene by the occupants of Quebrada Jaguay.

Quispisisa Obsidian in the Early Archaic

Another early use of obsidian in the Andes is the evidence of Quispisisa obsidian in levels dated to ~9000 uncalBP or 8500-7750 cal BCE (Burger and Asaro 1977;Burger and Asaro 1978;Burger and Glascock 2000;MacNeish, et al. 1980) from Jaywamachay a.k.a. "Pepper cave" (Ac335) located at 3300 masl in Ayacucho in the central Peruvian highlands. As was recently explained by Burger and Glascock (2000;2002), for nearly three decades the Quispisisa obsidian source was mistakenly believed to have been located in the Department of Huancavelica, but in the late 1990s the true Quispisisa source was finally discovered in the Department of Ayacucho. Jaywamachay is the closest of the sites excavated by MacNeish's team to the newly located Quispisisa source. It is 81.3 linear km or 22.0 hours walking calculated using the hiking function, while the bulk of the sites excavated by MacNeish were in the Ayacucho valley approximately 120 km from the relocated Quispisisa source. The Puzolana (Ayacucho) obsidian source is located close to the Ayacucho valley and high-quality, knappable obsidian is available at this source, but the maximum size for these nodules is 3-4 cm, significantly limiting the potential artifact size for pieces made from this source (Burger and Glascock 2001). It is interesting to note that, in several cases in the south-central Andes, the Archaic Period foragers seem to have ignored small sized or low-quality obsidian sources that later pastoralists ended up exploiting. The Aconcahua source near Mazo Cruz, Puno, previously described, was not used at the adjacent Qillqatani rock shelter until the Middle Formative (Frye, et al. 1998), and it was not used at Asana until the Terminal Archaic (Aldenderfer 2000: 383-384).

Burger and Asaro(1977: 22;1978: 64-65 )chemically analyzed a projectile point of Quispisisa obsidian found at La Cumbre in the Moche Valley that was reportedly from a context dated to 8585±280 bp or 8500-6800 cal BCE(Ossa and Moseley 1971). The investigator, Paul Ossa, now doubts the Early Archaic context and instead believes the point may be Middle Horizon in date (Richard Burger, 11 March 2006, personal communication), but it is still a noteworthy case of long distance transport within the Wari Empire, and it perhaps involved the use of coastal maritime transport. Using the relocated Quispisisa source in the Department of Ayacucho the linear distance is 846.7 km and by the hiking function the distance is calculated as 199.8 hours, primarily confined to the coast.

Discussion

Regional relationships indicated by both stylistic criteria and obsidian distributions point to high mobility during the Early Archaic Period. Recent evidence of projectile point similarities from northern Chile suggest that mobility was high along the Pacific littoral, and between the sierra and puna during the Terminal Pleistocene and Early Holocene around 25° S latitude(Grosjean, et al. 2005;Nuñez, et al. 2002). During the Early Holocene, foraging groups resided around high altitude paleo-lakes on the altiplano of northern Chile between 20° S and 25° S latitude that persisted longer than did the paleo-lakes at the latitude of Lake Titicaca. These lakes subsequently dried up during the Middle Archaic Period and occupations declined until the end of the Late Archaic Period but this distributions point to the mobility and early high altitude occupation of the adjacent puna of Atacama.

On the whole, obsidian proveniencing and analysis has shed light on human activities during the Paleoindian period and Early Archaic at a regional scale. Chemical analysis techniques, non-destructive XRF analysis in particular, are becoming more pervasive because the methods are being refined and the equipment is becoming more portable. Further field research will provide a greater understanding of this time period, but evidence will also likely to emerge from existing collections as obsidian projectile points diagnostic to the Early Archaic are systematically provenienced.

Obsidian distributions during the Middle Archaic

At the site of Asana on the western slope of the Andes, Aldenderfer(1998: 223)observed architectural features that suggest that a longer residential occupation of the site by entire coresidential groups was occurring in the latter part of the Middle Archaic Muruq'uta phase.One flake of obsidian from the Chivay source was found in the upper levels of theMuruq'uta phase (XTable 3-4X).This occupation dates to the Middle Archaic -Late Archaic transition as the flake was stratigraphically above a¹⁴Csample that dated to 6040 ± 90 bp (Beta-24634; 5210-4720 BCE).

At the rock shelter of Sumbay SU-3 obsidian was recovered from excavation levels that date to as far back as the transition between the Middle and Late Archaic (SectionX3.4.3X).

Discussion

Relatively little is known about the Middle Archaic in the south-central Andean highlands. Elsewhere in the south-central Andes, archaeologists have noted an absence of settlement during the mid-Holocene timeframe corresponding to the Middle and Late Archaic Periods. In the dry and salt puna areas of northern Chile, and along the south coast of Peru, a significant decline or absence of mid-Holocene sites has led investigators to refer to this period as the silencio arqueológico(Nuñez, et al. 2002;Núñez and Santoro 1988;Sandweiss 2003;Sandweiss, et al. 1998). This designation apparently does not apply to the Titicaca Basin or to the sierra areas of the Osmore drainage where no Middle Archaic occupation hiatus has been observed.

With gradual population increases and adaptation to the puna, social networks extending across the altiplano and connecting communities and their resources residing in lower elevations with puna dwellers, were probably beginning to take form. Exchange of resources, including obsidian, between neighboring groups may have been in the context of both maintaining access to resources and risk reduction. From a subsistence perspective, Spielmann (1986: 281) describes these as buffering, a means of alleviating period food shortages by physically accessing them directly in neighboring areas, and mutualism,where complementary foods that are procured or produced are exchanged on a regular basis. Another likely context for obsidian distribution during the Archaic Period is at periodic aggregations. Seasonal aggregations have been well-documented among foragers living in low population densities, where gatherings are the occasion for trade, consumption of surplus food, encountering mates, and the maintenance of social ties and ceremonial obligations (Birdsell 1970: 120;Steward 1938). If analogous gatherings occurred among early foragers in the south-central Andes it have would created an excellent context for the distribution of raw materials, particularly a highly visible material like obsidian that was irregularly available in the landscape.

Chivay obsidian during the Late Archaic

Evidence of Late Archaic obsidian use comes from excavations at the previously discussed sites of Asana, Qillqatani, and Sumbay. Several obsidian samples in the Burger et al. (2000) study were of portions of diagnostic projectile points that resemble types in Klink and Aldenderfer's (2005) point chronology. From illustrations and text(Burger, et al. 2000: 279, 281)the Qaqachupa sample appears to belong to the Late Archaic. Burger et al. describe this point as resembling a Type 7 point from Toquepala in Ravines'(1973)classification, and Klink and Aldenderfer(2005: 44)mention that their Type 4D point strongly resembles the Toquepala Type 7, making it diagnostic to the Late Archaic.

Discussion

Obsidian from securely dated Late Archaic contexts show something of a reduction in regional distribution and a greater focus on locally available lithic material, suggesting a reduction in mobility or exchange in the Late Archaic. Similarly, projectile point styles became increasingly more limited in spatial distribution, with greater local variability during the Late Archaic implying reduced mobility(Klink and Aldenderfer 2005: 53). This is consistent with Aldenderfer's(1998: 260-261)observations about reduced mobility during the Late Archaic Qhuna Phase occupation at Asana when the occupants ceased to use non-local lithic raw materials. During this phase, Aldenderfer also describes increasingly formalized use of space at Asana, evidence of a ceremonial complex, and greater investment in seed grinding. In short, during this time a circumscribed population with reduced mobility was probably living in higher densities and exhibiting signs of ceremonial activity that are consistent with the scalar stress model for the emergence of leadership(Johnson 1982).

It is also worth considering the impact that scarcity may have on valuation. The lack of discarded obsidian signifies that it was not being knapped or resharpened and it was probably not abundant, but that does not mean that obsidian was not known in the larger consumption zone during this period. In the subsequent time period, the Terminal Archaic, obsidian becomes abundant on a regional scale at the same time as a host of other social and economic changes were occurring. This period, and the previously discussed Middle Archaic, correspond with what was referred to as the silencio arqueologico(Núñez and Santoro 1988)due to a dearth of archaeological data observed by investigators working in Northern Chile. The reduced evidence of circulation of obsidian from Chivay appears to correlate with a reduction in archaeological evidence regionally.

Thereis strong representation of Chivay obsidian in Arequipa at Sumbay, and it is likely that Late Archaic projectile point forms are found in the North Titicaca Basin as reported by Burger et al. (2000). However, at Asana there is little obsidian from the Colca. Possibly these reduced distributions of obsidian reflect the reduced mobility and more complex architectural investment in Late Archaic contexts at Asana(Aldenderfer 1998), and prior to the development of extensive, long distance exchange that were potentially initiated by early caravan networks during the Terminal Archaic.These conclusions, however, on not based on particularly robust data, as the sample of sites for this time period is relatively small.

Chivay obsidian during the Terminal Archaic

While the number of excavated Terminal Archaic sites is relatively small, general processes are apparent from recent work at several sites in the south-central Andean highlands.

At Ch'uxuqullu on the Island of the Sun, Stanish et al.(2002)report three obsidian samples from the Chivay source in Preceramic levels. Eight obsidian flakes were found in aceramic levels and were described as being from a middle stage of manufacture, and three of these were sourced with NAA. Two samples came from levels with a¹⁴C date of 3780±100bp (Teledyne-I-18, 314; 2500-1900 BCE) and a third Chivay obsidian sample comes from an aceramic level that immediately predates the first ceramics level which occurred at 3110±45bp (AMS-NSF; 1460-1260 BCE). Citing paleoclimate data, the authors observe that boat travel was required to access the Island of the Sun at this time.

Other obsidian types during the Terminal Archaic

Obsidian from alternative sources in the circum-Titicaca region, including the unlocated sources of Tumuku and Chumbivilcas types, are used in greater quantity during the Terminal Archaic judging from associated projectile point evidence provided in Burger et al.(2000: 280-284).

Evidence from close to the Alca obsidian source provides new information about long distance interaction during Terminal Archaic. At the site of Waynuña at 3600 masl(Jennings 2002: 540-546)and less than one day's travel from the Alca obsidian source, recent investigations have uncovered a residential structure with evidence from starch grains resulting from the processing of corn as well as starch from arrowroot, a plant necessarily procured in the Amazon basin(Perry, et al. 2006). Given the long distance transport of arrowroot, it is conceivable that the plant material arrived as a form of reciprocation or direct transport from travelers moving between the Amazon and the Alca obsidian source. The Cotahuasi valley also has major salt source and other minerals that would potentially draw people procuring such materials. The starch samples were found in a structure on a floor dated by two¹⁴C samples. One sample was dated to 3431±45 (BGS-2576) 1880-1620 BCE, and another was 3745±65 (BGS-2573) 2350-1950 BCE

Further north, the Quispisisa type obsidian was particularly abundant during the Terminal Archaic at the preceramic coastal shell mound site of San Nicolas, along the Nasca coast, in a context associated with early cotton(Burger and Asaro 1977;Burger and Asaro 1978: 63-65). Quantitative data on the consumption of obsidian at San Nicolas are unavailable and the temporal control is weak because the "cotton preceramic" date is derived from association with cotton and no ceramics, not from direct¹⁴C dating.

Discussion

The distribution of obsidian from all three major Andean obsidian sources: Chivay, Alca, and Quispisisa, expanded considerably during the Terminal Archaic. It is notable that both the Chivay and Alca sources expanded, but the distribution remained confined to the sierra and altiplano areas of the south-central Andes. In comparison, obsidian from the Quispisisa source (340 linear km to the north-west of the Chivay source), has been found in significant quantities in Ica on the coast of Peru. While many of the early coastal obsidian samples have weak chronological control, the quantities of Quispisisa obsidian found in possible Archaic contexts is noteworthy. The fact that Chivay obsidian has never been found in coastal areas, and Alca is not found on the coast after the Paleoindian period, is remarkable considering the extensive evidence of coastal use of Quispisisa obsidian beginning in the Terminal Archaic.

Chivay obsidian distributions

At Qillqatani, obsidian flakes are available in quantity during this Titicaca time period which roughly overlap with the Formative A and B (XTable 3-5X). Seven obsidian samples were analyzed at MURR that all corresponded with the Chivay source. These samples were found in levels adjacent to a context that dated to2940±70bp (Beta-43925; 1380-970 BCE).

It appears that obsidian was being obtained as nodules or blanks and being knapped down to projectile points. Obsidian flakes represent 15% by count (n = 160) of all the flakes in the period "Formative A", and obsidian projectile points represent 12% by count of all points in this level(Aldenderfer 1999).

Obsidian is first found at Qaluyu dated to ~3250 uncal bp which calibrates to 1640-1420 BCE(Burger, et al. 2000: 291-296), or the end of the Early Formative where Burger et al. report evidence of nodules or blanks arriving for further reduction at the source. Some of the Chivay obsidian found at Qaluyu were medium sized pebbles; one example Burger et al. analyzed had the dimensions 1.9 x 1.4 x 1.2 cm. Qaluyu is 140 linear km from the Chivay source, or 34.6 hours by the hiking model, so it is roughly 70% of the distance of Qillqatani from the source. There are substantial quantities of obsidian at Qaluyu during the subsequent Middle Formative.

Discussion

Paleoclimatic studies have documented a decline in abundance of arboreal species in the Lake Titicaca Basin and an increase in open-ground weed species reflecting disturbed soils after ca. 1150 cal BCE(Paduano, et al. 2003: 274). This has been interpreted as reflecting intensification in food production and population that occurred during the Early Formative. Some argue that the grasslands of the altiplano are an anthropogenic artifact of a human induced lowering of the treeline due in part to the expansion of camelid pastoralism(Gade 1999: 42-74). The increasing sedentism, cultivated plants, expanding camelid herds and the growing influence of prominent settlements like Qaluyu in regional organization signify that significant socio-economic dynamism was underway by this period. The evidence of hierarchy takes the form of "very moderate social rank" acquired by certain individuals, such as religious specialists(Stanish 2003: 108). These traits are first suggested by jewelry, grave goods, and non-residential structures in the Terminal Archaic, but they become further elaborated during the Early Formative after 2000 BCE.

There is no evidence of political ranking in the structure of settlement distributions between Early Formative sites in the Lake Titicaca Basin, and all the sites are less than one hectare in size(Stanish 2003: 108), but the evidence of obsidian circulation from Qillqatani and other pastoral sites suggests of regional exchange system not yet focused around Lake Titicaca. Evidence acquired from the earliest occupational levels at Titicaca Basin regional centers suggest that regional interaction was low. At the site of Chiripa, in the southern Lake Titicaca Basin, Matthew Bandy describes traces of sodalite beads, obsidian, and sea shell in excavations from Early and Middle Formative contexts.

It is clear, then, that long distance trade in mortuary and prestige items took place as early as the Early Chiripa phase [1500-1000 BCE]. Equally clear, however, is that this early exchange involved very small quantities of the objects in question. This trading would seem to have been very sporadic and infrequent. There is no evidence in the Early Formative Period for the sort of regular caravan trade postulated by Browman (his "altiplano mode"; see Browman 1981: 414-415) (Bandy 2001: 141).

However, the evidence for obsidian distributions at Qillqatani that are discussed here point to routine exchange, perhaps by caravan trade, along on the Western Cordillera in the Early Formative. It appears that future regional centers like Chiripa were not yet participants in these exchange networks.

The dynamic nature of interregional interaction that occurred during the Early Formative is evident from the diversity in obsidian types at sites, and the lack of geographical restrictions that appear to structure exchange during later periods. While settled communities were evident, the lack of hierarchy and centralization suggests that they were not integrated by supra-local organization. Yet the economic basis for long distance relationships appears to have taken form by the Early Formative. The decentralized and variable nature of exchange in this period, which is abundantly evident at Qillqatani and yet not evident at sites like Chiripa, implies that another form of integration was linking communities, like the residents of Qillqatani, with the Chivay source 221 km to the north-west.

Chivay obsidian distributions

Chivay obsidian occurs in small quantities at a number of Middle Formative sites in the southern Basin including Chiripa and Tumatumani, and it persists at Ch'uxuqullu on the Island of the Sun. At Tumatumani, 3% of the projectile points are made from obsidian(Stanish and Steadman 1994). Bandy(2001: 141)reports that at Chiripa they recovered only small quantities of obsidian in the time spanning 1500-200 BCE and these were in the form of finished bifaces. For the entire time span, after four excavation seasons, they report only 87.1g of obsidian. Tumuku type obsidian was identified in Chiripa in Condori 1B component circa 1500-1000 cal BCE levels(Browman 1998: 310, dates calibrated). At the site of Camata, on the lakeshore south of the modern city of Puno, four obsidian samples were analyzed from contexts that range from circa 1500 - 500 cal BCE and all four were of Chivay type obsidian(Frye, et al. 1998;Steadman 1995).

The evidence from the North Titicaca Basin regional centers is even more intriguing as there is a significant presence of Alca type obsidian during the early part of the Middle Formative, and Chivay obsidian is found in the Cusco Basin during this time. Qaluyu, Pikicallepata, and Marcavalle all contain both Chivay and Alca obsidian between approximately 1100 - 800 cal. BCE, the early part of the Middle Formative(Burger, et al. 2000: 292;Chávez 1980: 249-253). Subsequent to this overlap in obsidian use, there appears to have been significant overlap in other stylistic attributes as well. These similarities include common traits in ceramic vessel forms between Chanapata vessels in the Cusco area and Qaluyu vessels in the North Titicaca Basin(Burger, et al. 2000: 292).

However, during the latter part of the Middle Formative after 800 BCE the Yaya-Mama religious tradition first emerges at the site of Chiripa(Bandy 2004: 330;Chávez 1988), a tradition that eventually unifies the north and south areas of the Titicaca Basin during the Late Formative. As noted by Burger et al.(2000: 311-314), with the appearance of the Yaya-Mama tradition the Alca and Chivay obsidian distributions become more asymmetrical. Alca obsidian makes up 16% (n = 9) of the obsidian in a pre-Pukara context at the site of Taraco on the Titicaca lake edge in the North Basin, however while Chivay obsidian was found at Marcavalle and other Cusco sites previously during the Early Formative, obsidian from the Chivay source is absent during the Middle Formative and it does not re-appear in the Cusco region again until the Inka period. Alca obsidian, on the other hand, expands outward during this period as it is found in the Titicaca Basin to the south-east, and it is also is transported a great distance to Chavín de Huantar. Both of these examples of long distance transport have been attributed to religious pilgrimage(Burger, et al. 2000: 314).

Discussion

Middle Formative obsidian distributions appear to demonstrate the emergence of a distinctive Titicaca Basin exchange sphere. One could argue that the emerging elites that mobilized labor to build the initial mounds and courts, and sponsored specialized artistry in stone and ceramics, may have precipitated a demand for greater exotic exchange goods as a source of prestige. Stanish(2003: 162)believes that this is the process that occurs later, during the Late Formative, when he argues that this process is connected to wealth generation for sponsoring feasts and other activities, though he admits the data are sparse. Evidence of long distance exchange from contexts belonging to the Early Formative and first half of the Middle Formative (1500-1000 BCE) at sites like Chiripa are sparse, irregular, and generally involve very small, portable goods; however the evidence from Qillqatani supports other models of more regular interaction along established exchange routes.

Discussion

The decline in forest cover in the Lake Titicaca Basin beginning during the Early Formative intensified throughout the Formative Period. Between 2500 - 800 cal. BCE a decline in fine particulate charcoal was detected in a lakecore drawn from the southern end of Lake Titicaca's Lago Grande(Paduano, et al. 2003: 274). The pollen and charcoal record indicates thatforest cover finally disappeared around AD0, coincident with population increases and resource pressure associated with Late Formative Period socio-economic intensification.

The obsidian circulation during the Late Formative shows distinct patterns in the Titicaca Basin and in Cusco. In the Titicaca Basin, the diversity of sources is reduced, with virtually all the material coming from Chivay and Alca, and the Alca samples are primarily affiliated with a single period at Taraco. Even at the site of Qillqatani, the diversity is reduced as compared with the previous Middle Formative level (Qillqatani Formative C). Current evidence suggests that the economic circulation was more integrated and that it was probably under some form of control by the dominant regional centers of this time. The furthest confirmed evidence of Chivay obsidian transport is from among Late Formative contexts at Kallamarka and Khonkho Wankane.Yet, diagnostic evidence from Titicaca Basin Late Formative polities in the Colca valley area is scarce. Part of the difficulty in understanding the Formative at the Chivay obsidian source area is that the Formative ceramic sequence in the Arequipa highlands is still being refined.

Obsidian consumption at Tiwanaku

Research by Martín Giesso (2000;2003) on the Tiwanaku lithic industry has revealed patterns in the differential use of lithic material in the region. First, it should be noted that obsidian is not abundant in the Tiwanaku core area in terms of the capital of the expansive state. Giesso (2003: 365-366) notes that obsidian artifacts make up only 0.8% of the lithics by count (n=86), of the collections at Tiwanaku. Yet the Tiwanaku core lies 315 km from the Chivay source in Euclidean distance, or 70 hours by the hiking function and therefore while obsidian is relatively scarce, it has been conveyed a considerable distance. The spatial distribution and the artifact form of obsidian at Tiwanaku are more analytically relevant than the total count or weight of obsidian which was quite small. Intrasite data on the contrasts in temporal and spatial use of obsidian at Tiwanaku are critical because, among other things, these data would provide a gauge of the relative persistence of access to the Chivay source as Tiwanaku's regional influence expanded.

Giesso's comprehensive source sampling showed that ten different types of obsidian were in use in the Tiwanaku heartland, although of these ten samples only four samples derive from known source locations. He notes that of the ten obsidian types, only Chivay (Cotallaulli) type is transparent and rest are described as "opaque". Giesso's spatial assessment of the distribution of lithic production activities in the core region showed that obsidian microdebitage was concentrated at certain mounds and in residential sectors as compared with chert, quartzite, and other locally available products. Giesso also organized a sourcing study of basalt artifacts in the Tiwanaku area, and he examined the contexts of production at the Querimita quarry located on the southwestern shores of Lake Poopó in Bolivia (Giesso 2003: 369) just over 300 km south of Tiwanaku. The evidence from Querimita on the production and consumption of basalt provides an interesting regional contrast to the spatial patterning of Chivay obsidian. There are both Wankarani (Formative) and Tiwanaku sites in the vicinity of the Querimita basalt source in the direction of the shores of Lake Poopó, but diagnostic Tiwanaku materials at the quarry itself are not reported (M. Giesso 2006, pers. comm.).

At Tiwanaku, quantities of obsidian and quartz have been found in the construction fill at the ceremonial Mollo Kontu mound, a structure that has served as a local fertility shrine. Nicole Couture argues that "quartz and obsidian fragments also served as mountain icons, in the way that exotic crystals, minerals, and rock candies are used today by Aymara yatiris, or ritual specialists, to represent mountains and thunder in rites to promote agricultural and social fertility" (Couture 2003: 225). Obsidian from Mollo Kontu has been traced to six different sources: Quispisisa, Chivay, Sora Sora, Cerro Zapaleri, and two unlocated sources (Giesso 2000). "The high density of quartz and obsidian artifacts, often five to ten pieces per excavation level, indicates that they were not accidentally included as part of redeposited rubbish, but rather were deliberately added to the clay fill" (Couture 2003: 215). The diversity in the Tiwanaku urban core was such that Chivay material represented a relatively low percentage (76%) of the material, although the ratio of Chivay material in Giesso and Glascock's study on the whole was 90% Chivay, which is typical for the Titicaca Basin. Interestingly, Giesso found that the 19 obsidian samples from the Akapana and Putuni were all transparent samples from the Chivay source, a pattern supported by the ceramics assemblage from those sites that was entirely local. This pattern suggests to Giesso (2003: 368) that a cultural strategy of "ideological purity" was taking place at that location at Tiwanaku due to exclusive use of those particular materials that are perceived as "local" to the Titicaca Basin. Giesso notes that obsidian is found in the form of standardized projectile points, type 4E according to Klink and Aldenderfer (2005), and that evidence of production is found in commoner residential contexts, whereas finished points are often associated with elite ritual contexts. This suggests to Giesso that labor contributions for some segment of the Tiwanaku heartland commoner population may have taken the form of projectile point manufacture.

A comparison of the circulation and use of Chivay obsidian with Querimita basalt strongly suggests to Giesso that the source areas, production, and transport of both exotic materials were controlled by the Tiwanaku state. If so, research at the Chivay source should reveal some evidence of Tiwanaku materials as it did at Querimita, and perhaps research will reveal state mandated standardization of production activities. However, if no evidence of Tiwanaku presence is found at the Chivay source, then this suggests that the relationship between raw material procurement, long distance transport, and state sponsored activities involved a more nuanced relationship between the state and the peripheral economy.

Burger et al. (2000) also analyzed obsidian from Tiwanaku and in their study, from a collection of 18 samples, all from surface contexts, the results were all of the Chivay type. The original Burger and Asaro (1977) study of Bolivian obsidian revealed that three samples purportly from the site of "Sora Sora" were from the Titicaca Basin source, now known as the Chivay source. At 554 km from the Colca Valley this is the furthest reported transport of Chivay type obsidian to date. However, some doubts have arisen as to the spatial origin of these three samples supposedly from the site of Sora Sora (Burger, Dec 2006, pers. comm.), and given the anomalously high transport distance, these three samples are suspect unless additional supporting data become available. The second furthest reported conveyance of Chivay obsidian is 325 km to the Late Formative contexts of Kallamarka and to Khonkho Wankane in Bolivia, as mentioned above.

Obsidian consumption at Wari

At the imperial capital of Wari, obsidian flakes were likewise found in domestic contexts and have been interpreted as "kitchen waste" as no specialized obsidian production sites were found at the site of Wari (Isbell, et al. 1991: 48; contra ;Stone 1983). In the funerary area of Wari known as the Cheqo Wasi sector the obsidian artifacts include a broken knife, 79 flakes (both utilized and unutilized), and two triangular fragments of obsidian with flat surfaces that may have been polished mirrors (Benavides 1991: 64).

At the Wari site of Pikillacta, in the valley of Cusco, evidence from obsidian flakes found in household compounds suggests that obsidian production took place at the household level. In the Haycuchina and Waska Waskan residential clusters, evidence of craft production consists of "waste flakes" of turquoise-colored stone, obsidian, and broken marine shell all collected from the surface (McEwan 1991: 99). Obsidian flakes were found in middens at Pikillacta along with both utilitarian and elite ceramics.

The Colca area during the Tiwanaku Period

Relatively little is known about the Colca valley in time periods prior to the Late Intermediate period. The political context of the Colca during this time is intriguing and somewhat ambiguous because the Colca valley lay on the frontier between Wari and Tiwanaku. External cultural influences in the Colca valley proper during the Tiwanaku times appear to have been entirely from Wari, yet Chivay obsidian is not found in Wari sites except in sites with a Tiwanaku component in Moquegua. Given the predominance of Chivay obsidian at Tiwanaku one might expect to encounter diagnostic Tiwanaku material somewhere close to the Chivay source. A number of scholars have commented on the surprising lack of Tiwanaku material in the Colca area given the obsidian distributions in the Tiwanaku heartland (Brooks 1998: 311-313, 454-459;Brooks, et al. 1997;Burger, et al. 1998: 211-212;Burger, et al. 2000: 340-342;).

The geographically closest Tiwanaku sites to the Colca in the department of Arequipa are found on the south-west edge of the city of Arequipa (85 km due south), with the best evidence coming from the site of Sonqonata (Cardona Rosas 2002: 78-87). The Arequipa highlands are largely unstudied, and the closest known Tiwanaku site to the Chivay source on the altiplano appears to be 147 km to the east in the department of Puno at the site of Maravillas just north of Juliaca (Stanish 2003: 189). Tiwanaku sites in this region are generally associated with lakeside agriculture or are found at cross-roads along major travel corridors (C. Stanish March 2006, pers. comm.), and to date no Tiwanaku sites are known in the largely pastoral periphery of the northwestern Lake Titicaca Basin in the direction of the Chivay source. Tiwanaku pottery has been found in Cuzco at Batan 'Urqo (Glowacki 1996: 245) and a Tiwanaku snuff tablet was found at La Real in the lower Majes valley of coastal Arequipa (García Márquez and Bustamante Montoro 1990: 28), but these appear to have been examples of trade goods along the Tiwanaku-Wari frontier.

In the main Colca valley close to the Chivay source, Wari-related ceramics have been excavated from a site just 4 km downstream from the town of Chivay and approximately 10 km from the Chivay obsidian source. A trench excavation exposed red-slipped wares from a domestic context with Tiwanaku Horizon dates in archaeological work associated with the William Denevan's Río Colca Abandoned Terrace Project at the site of Chijra (Malpass 1987: 61;Malpass and De la Vera Cruz 1986: 209, 216;Malpass and De la Vera Cruz 1990: 44-46, 57). Radiocarbon dates associated with these red-slipped wares came from a hearth in a house terrace and produced dates of 1140 ±80 (WIS-1713; AD680-1030) and 1290±90 (QL-4015; AD600-900) (Malpass 1987: 61). This ceramic style has recently been investigated in detail by Wernke as part of his elaboration of the Colca valley ceramic sequence (Wernke 2003: 466-477). Other Wari-influenced sites in the Colca Valley include a large, recently located site in on the north side of the Colca river named Charasuta close to the town of Lari (Doutriaux 2004: 212-223) and the site of Achachiwa near Cabanaconde (de la Vera Cruz 1987;de la Vera Cruz 1988;Doutriaux 2004: 202-207). Curiously, Chivay obsidian is not known to have circulated in the Wari sphere at all despite the proximity of these sites to the Chivay source.

In the main Colca Valley, indications of Wari ideological and stylistic influence are the strongest evidence for external links during the Tiwanaku Horizon. In addition to Wari influences at Chijra and Charasuta, the site of Achachiwa provides intriguing evidence of exotic obsidian intruding into the Colca valley. Achachiwa is a large site adjacent to the modern town of Cabanaconde that has a large Middle Horizon component that appears to be Wari influenced, as well as components belonging to a the local LIP occupation and an Inka occupation (de la Vera Cruz 1987;de la Vera Cruz 1988;Doutriaux 2004: 202-207). Brooks reports that she collected seven obsidian flakes for analysis from Achachiwa that were visually distinct from obsidian she had encountered elsewhere in the Colca (Brooks 1998: 447). Of these seven flakes, none were of Chivay type obsidian although the site is only 46 km downstream of the source. Her analysis showed that six of the flakes were from the Alca source (96 linear km away) and one was from the Quispisisa source (300 km away), a strongly asymmetrical pattern that is non-the-less consistent with Middle Horizon obsidian distributions in southern Peru.

Discussion

Chivay obsidian distributions during the Tiwanaku period are somewhat of an enigma. As Tiwanaku persisted for longer than Wari one might expect Tiwanaku evidence at the Chivay source either preceding or simultaneous with Wari presence in the Colca valley. However, the nature of procurement and distribution of Chivay obsidian during the Tiwanaku period was such that diagnostic materials from the consumption zone do not appear at the Chivay source. There appears to have been considerable nuance in the relationships between state leaders, corporate integration, and ethnic local kin-based groups during the period of Tiwanaku hegemony. Groups living in the Tiwanaku peripheral areas were perhaps consistent with Dillehay's characterization as"…a patchwork of overlapping, geographically disparate, and apparently politically semi-autonomous core valleys, oases, and plateaus or foci of cultural development, each of which primarily exploited its own immediate peer area"(Dillehay 1993: 247). Along these lines,Stanish (2002: 188) notes that early states appear to have "selectively incorporated certain areas around the basin" rather than attempt comprehensive control. John Janusek summarizes a variety of evidence demonstrating that "Tiwanaku was an incorporativemore than it was a transformativestate, simultaneously employing multiple strategies of regional control and influence" (Janusek 2004: 162), along the lines of corporate political strategies described by Blanton et al.(1996). Accordingly, a direct correlation between the predominance of Chivay obsidian in the Tiwanaku economy and clear, material evidence of incorporation in the archaeological remains of communities in the Chivay source area should not be expected. The political affiliation of Colca valley communities was probably made more complex due to the presence of the Wari frontier during the Middle Horizon.

The asymmetrical, export-only exploitation is consistent with a pattern that has been observed at a number of prehispanic obsidian sources in the Andes. Obsidian sources generally have few diagnostic artifacts or architecture in association with quarrying. It was mentioned earlier that Formative distributions of Alca obsidian were strikingly asymmetric with export to long distance consumption sites but no corresponding diagnostics from those consumers back at the Alca source (Burger, et al. 2000: 314, 323). Similarly, the Quispisisa source has little diagnostic evidence the immediate vicinity linking the source to Wari or any other known group, despite the long history of use of that obsidian type in Wari sites (Burger and Glascock 2000;Burger and Glascock 2002). The asymmetrical nature of Chivay obsidian use during the time of Tiwanaku and Wari is, therefore, consistent with a pattern apparent at raw material sources elsewhere in the Andes where obsidian procurement does not involve reciprocation or discard of diagnostic artifacts from the consumption zone.

Chivay obsidian during the LIP

In a review that considers the LIP and Late Horizon together in one discussion, Burger et al.(2000)note the declining presence of obsidian in most LIP and LH contexts in the region. Many of the chemically provenienced obsidian samples from the Titicaca Basin come from surface contexts with either LH or LIP associations, and the pattern revealed in the Titicaca Basin from these samples is one of almost exclusive use of Chivay type material. One of the reasons for the strong presence of Chivay obsidian over Alca obsidian may have resulted from cultural affinities between Aymara groups(Browman 1994). The Colla in the North Titicaca Basin and the Collagua in the upper Colca area share many traits including the construction of pukaras(Wernke 2003: 262-263), mortuary features including chulpaburial structures and fiber-wrapped mummy encasings(de la Vega, et al. 2005;Wernke 2003: 225-234), and other commonalities.

In the northern Lake Titicaca Basin, Arkush(2005: 247)notes that two-thirds of the occupied pukaras throughout her survey area contained obsidian on the surface, and that chert flakes and blades are common. In one instance, at Calvario de Asillo (AS1) prepared obsidian cores and a concentration of flakes was encountered. Obsidian projectile points were small, triangular base-notched points (series 5), consistent with the Klink and Aldenderfer point typology for the Terminal Archaic and onwards(Arkush 2005: 709-711). Metal objects are common as well, with copper and copper-alloy pendants and tupus(long pins) frequently found at pukaras.

Six obsidian samples from the mesa-top pukaraand chulpaburial tower complex of Cutimbo were analyzed by Frye et al.(1998)and the samples were 100% from the Chivay source. Burger et al.(2000: 343-344)indicate that one obsidian sample from the renowned chulpacomplex of Sillustani was also from the Chivay source. Burger et al. observe that while a single Alca flake was excavated at Taraco from an LIP context, and another was found on the surface at the LIP or LH site of Kolkeparke near Ayaviri(Burger, et al. 2000: 343), the Titicaca Basin is otherwise entirely supplied from the Chivay source during the LIP.

At the rock shelter of Qillqatani (SectionX3.4.2X) a large percentage (15.4%) of the tools from LIP levels were made from obsidian, although the count is very low (n = 2) and the tools were extremely small. The single obsidian sample that was analyzed proved to be from the Chivay source.

In the south-western Lake Titicaca area, Hyslop(1976: 118-119)found that the Lupaqa sites he encountered in the course of his road system survey contained primarily basalt and quartzite flaked stone. More recent survey work in the Ilave and Huenque drainages(Klink and Aldenderfer 1996)found that high-quality cherts are abundant in the region, which suggests that the prominent use of basalt at the sites Hyslop encountered was by choice, not by necessity, and was perhaps a reflection of lakeshore agricultural activities.