Date of Award:
Master of Science (MS)
Sociology, Social Work, and Anthropology
Judson Byrd Finley
Molly Boeka Cannon
Lithic source analysis, or “sourcing,” is a geochemical compositional analysis of lithic materials for both major and trace elements. Sourcing analysis assigns lithic sources to geochemical groups according to distinct geochemical compositions, where unique elemental signatures represent separate lithic sources. In archaeological research, sourcing informs upon mobility strategies, trade and exchange networks, and lithic conveyance studies. While obsidian sourcing is a relatively reliable and popular technique, chert sourcing is more difficult and historically less successful largely due to variability in chert formation processes. X-ray fluorescence spectrometry (XRF) offers a possible sourcing technique, and is non-destructive, as well as time and cost-effective. In this thesis, I test the reliability of XRF in determining the geochemical characterization of Tosawihi Quarries chert, a unique chert source located in the Humboldt River Basin of north-central Nevada.
The Tosawihi Quarries archaeological district (26EK6624) is a significant lithic resource that has hosted human occupation and activity for millennia. The Tosawihi Quarries offers a high quality toolstone that was intensely used, as indicated by numerous quarry locales and biface tool caches. Additionally, the Tosawihi Quarries is a social identity marker for the Tosawihi band of Western Shoshone, also serving as a source of spirituality and medicine. Tosawihi chert is a distinct, white lithic material type that also has a characteristic fluorescence pattern when exposed to ultraviolet light. While these are defining attributes, they are not unique to Tosawihi chert, as they occur in other Great Basin white chert sources. Identifying Tosawihi chert has been problematic, and misidentifications may have led to erroneous interpretations of the archaeological and ethnographic records. If successful, a geochemical characterization by XRF would provide an elemental signature specific to Tosawihi chert, thus eliminating discrepancies in visual and ultraviolet fluorescence readings and permitting archaeologists to accurately asses the distribution and use of this sacred material.
In this thesis research, I first conducted an XRF analysis of a source standard collection of Tosawihi Quarries chert, which yielded a preliminary methodology for identifying Tosawihi chert. This protocol was tested against two comparative collections of other Great Basin white cherts: Mono Lake Spillway located in western Nevada and Pahute Mesa (26NY1408) located in southern Nevada. The methodology, now refined, was then run against the archaeological collection, where five collections of white chert artifacts were tested for the presence of Tosawihi chert. Incorporating both the qualitative and quantitative data from XRF analysis, the results show that this proposed methodology can successfully discriminate between Tosawihi chert and other Great Basin white cherts based on its XRF signature.
Wurster, Bethany M., "A Geochemical Analysis of Tosawihi Quarries Chert Using X-Ray Fluorescence Spectrometry" (2019). All Graduate Theses and Dissertations. 7526.
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