Discussion

This test unit appears to show several occasions of obsidian reduction in conjunction with camelid butchering and cooking during the earliest part of the Tiwanaku period at this site in the upper Colca. More advanced reduction was occurring on obsidian, but there appeared to have been little preference for Ob1 obsidian over the Ob2 material, and in fact in the production of bifaces it appears knappers used Ob2 preferentially, though both materials were available. The Uyo Uyo obsidian source is under 40 km downstream and there are irregularities in Uyo Uyo material that such that it falls in the Ob2 category.

As dates contemporary with Tiwanaku were derived from this unit, a regional consideration of this occupation should include the distributions of Chivay obsidian in this time period. Regional distributions indicate that during the Tiwanaku period Chivay obsidian was rarely used north of Chivay source area. Distributions tend strongly towards the south and east where the Lake Titicaca Basin consumption pattern is strongest. Yet it is curious that the highest density of obsidian in the Block 3 area north of the source is dated to the Tiwanaku period, which is in a northward direction and towards the Wari sphere. In concordance with regional obsidian distributions in this time period, it is notable that the heavy use of Ob2 obsidian, and the production of bifaces rather than projectile points, suggests that goods produced at this obsidian production area use were intended for modest local consumption.