The projectile point typology developed by Klink and Aldenderfer (2005) discussed previously (Figure 3-10) is applicable throughout the south-central Andean highlands. The authors state that in Arequipa the northern frontier of the region under consideration for this typology is the ríoOcoña or the Cotahuasi valley. The study used projectile points exclusively from excavated and dated contexts in order to identify elements of projectile points that changed through time. In Klink and Aldenderfer's (2005: 27-28) study, measures on points were measured in millimeters with a precision of 1/100^thof a millimeter, and angles were measured with a goniometer. The measures used include Length (mm), Shoulder angle (°), Maximum tool width (mm), Haft length (mm), Blade length (mm), Haft angle (°), and Basal width (mm), as well as derivative ratios of these measures. The typology was thus constructed to differentiate stylistic features that reliably distinguish time periods. Following this typology, Series 1 through 4 projectile points types are (with two exceptions) diagnostic to the Archaic Period prior to the advent of predominantly pastoral economies. Series 5 projectile points are diagnostic to the later, pastoralist periods that include a wide variety of socio-political and economic changes in the Andes.

During Phase II analysis of the Upper Colca project lithics analysis, an emphasis was placed on Series 1-4 projectile points because these points are the only diagnostic temporal evidence from surface contexts for a broad swath of human history in the Chivay source area.

Table 5-9. Proportion of analysis by projectile point typological group.

These data show that Series 1-4 projectile points were analyzed disproportionately in the Phase II lab work and resolving this discrepancy is a priority for future analysis of the collection. However, in the exploration of the data concerning Ob1 vs Ob2 obsidian types (heterogeneity of material), as well as artifact color and other characteristics, the analytical bias does not overly skew the results and interpretations. During Phase II analysis diagnostic projectile points were illustrated by Yepez.