From the Yenisei to the Yukon: Interpreting Lithic Assemblage Variability in Late Pleistocene/Early Holocene Beringia

13. Late Pleistocene and Early Holocene Assemblage Variability in Central Alaska

215 13. Late Pleistocene and Early Holocene Assemblage Variability in Central Alaska ben a. potter C urrent interpretations of late Pleistocene and early Holocene (14,000–7000 cal BP) assemblage variability in central Alaska rely on traditional cultural-historical frameworks originally constructed as provisional hypotheses (Dixon 1985:61; Powers and Hoffecker 1989:283–284). For the late Pleistocene of central Alaska, two archaeological constructs have received widespread acceptance, the microblade-rich Denali complex (West 1967) postdating the non-microblade Nenana complex (Powers and Hoffecker 1989). However, typological assignation of components is not unequivocal and consistent among researchers. For instance, early Holocene components like Eroadaway, Carlo Creek, Owl Ridge component 2, and Jay Creek Ridge have been alternatively assigned to the Nenana complex (Dixon 1993), the Denali complex (Bowers 1980; Mason et al. 2001), or the Northern Paleoindian tradition (Dixon 2001) on the basis of bifacial morphology or absence of microblades. In addition to this typological ambiguity, current cultural-historical frameworks do not address patterns of economy, seasonality , and land use strategies and changes in these strategies through time (explored in Potter 2008a, 2008b, 2008c). The descriptive nature of traditional culturehistorical approaches inhibits hypothesis development and testing relating to cultural change (Binford 1983, 2001: 9–26). Traditional cultural-historical methods of identifying and mapping the temporal distribution of “culturally diagnostic ” artifact types have been relatively unproductive in explaining assemblage variability in central Alaska (Potter 2005:70–80). One commonly used “diagnostic” is microblade technology, which has been shown to be present throughout central Alaska for nearly the entire period of human occupation, about 14,000–1000 cal BP (Potter 2008a). Formal artifact variation can be conditioned by many factors beyond normative perspectives of cultural determinism (Andrefsky 1994; Bamforth 1986, 1991; Binford 1973, 1979; Kuhn 1994; Odell 1988; Shott 1986; Torrence 1983). These conditioning factors influence creation , use, and deposition of tools and result in differences of type, quantity, and array among assemblages. Internal systemic conditioning factors include land use strategies (in terms of resource and habitat use and scheduling), mobility strategies (both along logistical and residential mobility continua), the role of storage, position of the site within the seasonal round and provisioning systems, and technological organization. Site-specific social and economic group characteristics are also important. For instance , mixed foraging groups may be expected to produce very different assemblages with respect to tool types and quantities than would all-male hunting parties. External factors that can condition assemblage variability include climate change, prey diversity, and prey abundance. Each individual component should not be assumed to reflect the entire range of technological variability of a given population. In this chapter I explore alternate avenues to identify and evaluate assemblage variability with respect to three of the most tractable conditioning factors: technology, subsistence, and habitat use. I derive empirical intersite and intrasite data from excavation and testing in the Tanana, Copper, and Susitna river basins (Potter 2008b). A large sample of dated components is necessary to evaluate these data, by offering controls on the faunal and lithic assemblages, site location, and inferential patterns of land use. A full exploration is beyond the scope of this chapter, which focuses on two elements of late Pleistocene/early Holocene technology: microblades (as side insets to composite points) and bifacial projectile points. Both are generally inferred to be weapon armatures and thus linked 216 Ben A. Potter 1968; Dixon 1985), and the components considered here have been subsumed under a limited number of complexes (Denali/American Paleoarctic, Nenana, Northern Paleoindian, or Chindadn). This database includes fifty-four components from thirty-seven sites (figure 13.1); component delineation follows the original investigators . Multiple dates on single stratigraphic and cultural contexts were averaged following Ward and Wilson (1978), providing a single age estimate calibrated using Calib 5. I grouped components into intervals of 1,000 calendar years by the median of each date range to mitigate the lack of precision of single-age estimators. Data from recent surveys in the Tanana basin (seventeen components within this period) are included (Potter, Gaines, et al. 2007; Potter, Reuther, et al. 2007). Lithic assemblage and associated faunal data are from more closely with subsistence and habitat use. The patterns identified in this study and results from recent excavations in the Tanana basin suggest that assemblages ascribed to the Nenana complex may reflect a subset of behaviors within a broader land use strategy of late Pleistocene foragers. Methods To evaluate the ambiguities of this record, I compiled a comprehensive database of all published...