Screening for breast cancer.

Abstract

One of the principal ways that researchers date archaeological sites is by using temporally diagnostic projectile points as index fossils; however, this practice has not been widely employed to date rock art sites. We use this approach here to test the hypothesis that the Great Basin Carved Abstract (GBCA) petroglyph style found in the northern Great Basin was produced by Paleoindians. Using frequencies of projectile points at 55 GBCA sites, we demonstrate that Paleoindian points are significantly overrepresented there relative to their occurrence on the general landscape, providing evidence that Great Basin populations produced rock art sometime during the Terminal Pleistocene/Early Holocene (TP/EH), ∼12,500–8000 radiocarbon years ago. Additionally, we examine several environmental variables at GBCA sites and propose a model of Paleoindian land-use in the northern Great Basin that highlights seasonal visits to uplands to procure geophytes (i.e., root crops).