164-4 Molecular Geoarchaeology: Efficacy and Utility of Biomarker Analysis of Late Quaternary Sediments from Spirit Eye Cave, Far West Texas

Session: Advances and Applications of Geochemistry in Archaeology

Presenting Author:

Jasmine Kidwell

Authors:

Kidwell, Jasmine¹, Hoggarth, Julie², Hockaday, William C.³, Fulton, James M.⁴, Schroeder, Bryon⁵

(1) Department of Geosciences, Baylor University, Waco, TX, USA, (2) Department of Anthropology, Baylor University, Waco, TX, USA, (3) Department of Geosciences, Baylor University, Waco, TX, USA, (4) Department of Geosciences, Baylor University, Waco, TX, USA, (5) Center for Big Bend Studies, Sul Ross University, Alpine, TX, USA,

Abstract:

The Chihuahuan Desert region of far west Texas remains understudied in terms of its cultural, climatic, and environmental past. Current paleoclimatological and environmental proxy datasets are few and inconsistent in time, resolution, and scope. Using sedimentary archives from cave deposits, we apply molecular geoarchaeological techniques paired with radiocarbon summed probability distributions to reconstruct human demographics, hydroclimate, and paleoecology of this region while generating new proxy datasets. This work focuses on recovery of molecular fossil lipids, or biomarkers, preserved in sediments. These biomarkers help to contextualize the environment and record information that may not be preserved in other records across the Chihuahuan Desert. From the sediments, the preserved leaf wax, fecal stanols, and other non-polar and polar lipids were extracted in a lab, characterized by Gas Chromatography-Mass Spectrometry, and then, select total lipid extracts were submitted for bulk lipid radiocarbon dating and bulk lipid δ¹³C. These data are paired with complimentary datasets such as major and trace elements from pXRF, total organic carbon and nitrogen, bulk sediment δ¹³C and δ¹⁵N, and computerized tomography measured density values. Together, these data are used to generate additional climatology and ecology proxy records, setting the stage for contextualizing human demographic variability from the Late Pleistocene through the Holocene to better understand how the earliest occupants of far west Texas responded to long-term climatological and ecological change. Here, we present the progress made, lessons learned, and direction of ongoing work while sharing the applicability of biomarker analysis in archaeological practice.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-4816

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