This article synthesizes the 2000s-era ''peopling of the Americas'' data drawn from molecular biology, osteology, and archaeology. Collectively, they suggest that colonization proceeded in two pulses, both originating in western Beringia, and before that, south-central and southeastern Siberia. The first pulse occurred circa 16 k-15 k cal. B.P. by watercraft along the coast of Beringia and western North and South America. The second took place 1,000 years later and involved proto-Clovis hunter-gatherers who used the ice-free corridor as a conduit south. At least eight North American sites dating as far back as the Last Glacial Maximum suggest that the peopling picture may eventually need to change to accommodate an earlier than previously thought migration through the ice-free corridor. For now, the data are not strong enough to support this scenario, but they are tantalizingly close.

Forty years ago, Knut Fladmark (1979) argued that the Pacific Coast offered a viable alternative to the ice-free corridor model for the initial peopling of the Americas—one of the first to support a “coastal migration theory” that remained marginal for decades. Today, the pre-Clovis occupation at the Monte Verde site is widely accepted, several other pre-Clovis sites are well documented, investigations of terminal Pleistocene subaerial and submerged Pacific Coast landscapes have increased, and multiple lines of evidence are helping decode the nature of early human dispersals into the Americas. Misconceptions remain, however, about the state of knowledge, productivity, and deglaciation chronology of Pleistocene coastlines and possible technological connections around the Pacific Rim. We review current evidence for several significant clusters of early Pacific Coast archaeological sites in North and South America that include sites as old or older than Clovis. We argue that stemmed points, foliate points, and crescents (lunates) found around the Pacific Rim may corroborate genomic studies that support an early Pacific Coast dispersal route into the Americas. Still, much remains to be learned about the Pleistocene colonization of the Americas, and multiple working hypotheses are warranted.

This paper reports the results of pilot-study efforts to develop methods to profile quartzite, a rock type to which geochemical and other sourcing techniques have only rarely been applied. The long-term goal of the research is to fingerprint sources of quartzite in the Gunnison Basin, southwest Colorado, used by Paleoindian people ca. 11,500-8,000 years ago to make stone tools. Success would facilitate reconstruction of Paleoindian mobility in the Southern Rocky Mountains and potentially anywhere prehistoric people used quartzite. The goals of this paper are more modest: to demonstrate that a small-scale exploration of sourcing techniques suggests reason for optimism that quartzites may be amenable to source discrimination. For the same twenty Gunnison Basin quartzite samples, this study evaluated petrography, ultraviolet fluorescence (UVF), wavelength dispersive X-ray fluorescence (WD-XRF), instrumental neutron activation analysis (INAA), and inductively coupled plasma mass spectrometry-both acid-digestion (AD-ICP-MS) and laser ablation (LA-ICP-MS)-as means to differentiate among the specimens and the sources they represent. Although more testing is needed to verify and refine our results, the study suggests there is potential for petrography, INAA, and both versions of ICP-MS to discriminate among quartzites from different source localities in the Gunnison Basin. The greatest potential for discriminating among different sources of quartzite in the Gunnison Basin may lie in a methodology combining petrographic analysis and LA-ICP-MS. Future testing is required to evaluate this two-fold approach.

This essay addresses the contentious issue of collaboration between archaeologists and artifact collectors. I argue that in many instances, alienating members of the collecting public is not just bad practice; such alienation itself also violates the Society for American Archaeology's (SAA's) Principles of Archaeological Ethics. I make my case by first exploring the SAA's ethical code. I focus initially on “stewardship” and “commercialization,” which many cite as reasons for rejecting relationships with artifact collectors. I then discuss other SAA principles that support the perspective that archaeologists should actively reach out to citizens with private collections whenever possible. Second, I present a case study exploring what the Clovis archaeological record might look like had archaeologists rejected the overtures of a century of collectors who brought Pleistocene finds to the attention of professionals. Had practitioners accepted only those Clovis sites free of collector involvement, our understanding of Clovis lifeways would be quite different from what it is today. This essay has two messages. First, collectors can advance, and have advanced, archaeology by reaching out to archaeologists willing to reach back. Second, our own code of ethics suggests that responsibly engaging artifact collectors is not just “okay,” it is its own ethical imperative.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights LA-ICP-MS Analysis of Quartzite from the Upper Gunnison Basin, Colorado (Pitblado et al.) • 402 samples of quartzite from 48 sources in the Upper Gunnison Basin were systematically sampled in the field and analyzed using LA-ICP-MS to determine the degree to which the sources can be discriminated from one another. • The long-term goal of discriminating the sources is to use the protocols developed to "source" quartzite tools and debitage by evaluating their degree of similarity vis-à-vis profiled quartzite sources. • The study assemblage provides a comprehensive and reliable estimate of the range of compositional variability in Upper Gunnison Basin quartzite. • Results show spatial and geochronological trends in quartzite elemental composition that can be exploited in the future in the Upper Gunnison Basin and perhaps more widely in the world. • A different methodological approach must be taken to sourcing culturally modified quartzite than is used in traditional and widely applied obsidian sourcing studies.