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).
At Qillqatani, the Middle Formative comprises the bulk of Formative B layers and all of the Formative C layers (see Qillqatani data in Section X3.4.2X). In Formative B layers, Chivay obsidian is the only type represented in the four samples that were analyzed and the lithic assemblage suggests that formal tools were not being produced at the site as no evidence of obsidian tools were found in these levels. Obsidian flakes, however, persist as 18% of the lithic assemblage from that level. Subsequently, in the Formative C level that begins around 900 BCE and corresponds approximately with the latter half of the Middle Formative as well as the rise of the Yaya-Mama tradition in the south Titicaca Basin, there is a distinctive shift in the use of obsidian at Qillqatani. Whereas all prior obsidian samples from Qillqatani were Chivay after the initial Middle Archaic sample, the obsidian samples in Qillqatani Formative C levels are only 60% from the Chivay source.
The other samples come from Aconcahua, a source of lower-quality obsidian that is near the Qillqatani shelter, and from Tumuku, an as-yet undiscovered source that may be located close to the three-way border between Peru, Bolivia, and Chile, and finally Alca obsidian occurs for the first and only time at Qillqatani in these levels. Given that Alca obsidian also occurs at Pukara, Incatunahuiri (surface) and at Taraco in quantity (16% of assemblage, n = 9), the presence of Alca obsidian at Qillqatani is consistent with the abundance of Alca material in circulation in that time. A sample of Alca obsidian has also been found on the Island of the Sun (Frye, et al. 1998), though it was from a surface context.
Table 3-6Xshows that obsidian tools in Formative C levels at Qillqatani are abundant (n = 19) and relatively large on average (1.21 g), and the non-obsidian tools were also very abundant (n = 187) for this level.