Powars II artifacts exhibit four postdepositional alterations that clarify earlier interpretations of the site assemblage and help discern between in situ and ex situ archaeological deposits ( SI Appendix, Postdepositional Alterations). Thus, the utility of discarded tailings as a transportable pigment source was limited compared to pure hematite, so they were discarded on site. Tailings encountered during our excavation were coated by hematite particles that could be knocked loose for use as pigment, but they washed clean to a blue ore when exposed to subaerial weathering. This supports the notion that tailings originated from a single quarry feature from which undesirable ore nodules were tossed aside and preferentially downhill so that site occupants could reach deeper hematite deposits. Based on evaluation of the site’s exposed southern margin and limited testing, quarry tailings appear to grow thinner with distance from the quarry feature and in the upslope portions of the site. Tailings form the primary clast-sized archaeological matrix at Powars II, while fine-grained derivatives of hematite and hillslope sediments fill interstices between them. The quarry is surrounded by an extensive tailings deposit comprised of discarded iron ore nodules that covers an area of at least 800 intact square meters ( SI Appendix, Excavation Procedures and Fig. ( D) Three-dimensional photogrammetry rendering of the south wall of archaeological trench. ( C) Three-dimensional photogrammetry rendering of the north wall of archaeological trench. Margins of bedrock quarry pits are outlined with small dashed lines. ( B) Three-dimensional photogrammetry rendering of the completed archaeological trench facing west. Location of Frison’s 1986 informal test (2), location of Powars’s initial discovery at south end of quarry feature (3), historic mine adit uncovered during salvage excavations between 20 (4), an aerial drone image looking straight down on site in 2017 to show the relationship between the archaeological trench and the quarry feature. The known extent of buried archeological deposits is indicated as a large dashed line, and quarry feature margins are indicated with a small dashed line (1). The 6-m by 1-m excavation trench is visible near the center of the image. ( A) Aerial drone image of the Powars II site during excavations in 2017 facing north. Annotated overview of site settings and archaeological deposits. Nonlocal chipped stone raw materials indicate ties to much of the North American Great Plains, suggesting that Powars II hematite may be found in sites throughout the American midcontinent.įig. In situ archaeological deposits at Powars II are distinguished from overlying ex situ strata by sediment characteristics, bone preservation, patina development on chipped stone artifacts, diagnostic weaponry assemblages, and damage to flake margins. The earliest Clovis and Plainview occupations contain a diverse assemblage of stone and faunal artifacts indicative of hematite quarrying, weaponry production and repair, and other tasks, while the later Hell Gap occupation is primarily focused on hematite quarrying and the placement of items in piles within an abandoned quarry feature. Later occupation by the Hell Gap cultural complex intruded within previous quarry tailings and likely dates to ca. associated with the Clovis and Plainview cultural complexes. We document a deeply buried, bedrock-adjacent stratum containing in situ evidence for hematite quarrying beginning ca. We present results from controlled excavations at the Powars II Paleoindian hematite quarry (48P元30), located in the foothills of the southern Rocky Mountains in Wyoming.
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