21 D1. Geophysics and Remote Sensing Applications

Tuesday, 10 March 2020
8:00 AM - 12:00 PM
Meeting Room 201A

DUNE MIGRATION, PALEOSOLS AND PROJECTILE POINTS: NEW GEOARCHAEOLOGICAL INSIGHTS ON THE SOUTH TEXAS SAND SHEET

Paper number: 21-6
Program: Technical Sessions
Time: 9:25 AM – 9:45 AM

Authors

Abstract

The South Texas Sand Sheet (STSS) spans ~7,000 km2, and consists largely of sand sheet deposits, stabilized by vegetation, mostly under three meters thick, with active SE-NW longitudinal dune ridges near the coast. Evidence of human presence on the STSS in pre-Hispanic times is sparse. Archeological investigations are limited and have revealed a record characterized by low preservation of non-lithic remains, and overall very sparse cultural vestiges. Chronology of human occupation, subsistence strategies, and settlement patterns remain poorly known.

An isolated migrating dune at the center of the STSS, has exposed projectile points and abundant debitage, indicating human presence and perhaps a rich archaeological record buried beneath the sand. Preliminary findings from an ongoing investigation at this unique site include: 1) evidence of human occupation, dating back to the Early Archaic (Abasolo projectile points) and perhaps Paleoindian times, suggested by a single Golondrinas point. 2) the archaeological horizon sits on a well-developed paleosol, classified as an Oxysol, formed on a vegetated eolian deposit, indicative of a wetter climate and a stable landscape, and 3) a period of landscape instability between ~11,000 and ~4,000(?) years before present constrained by four optically stimulated luminescence ages from the buried dune. The lack of organic materials, which were likely lost to deflation, has precluded establishing an absolute 14C chronology for the time of human occupation.

Geological Society of America Abstracts with Programs. Vol. 52, No. 1

doi: 10.1130/abs/2020SC-343752

© Copyright 2020 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.