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.