103 D14. Geoheritage Discipline Session

Monday, 10 October 2022
1:30 PM - 5:30 PM
406

MOUNT BONNELL AS AN URBAN GEOHERITAGE SITE IN AUSTIN, TEXAS

Paper number: 103-12
Program: Technical Sessions
Time: 4:15 PM – 4:30 PM

Authors

  • Charles Woodruff
    Jackson School of Geosciences, University of Texas at Austin, Austin, TX
  • Linda Mccall Presenting Author
    Jackson School of Geosciences, University of Texas at Austin, Austin, TX
  • Francine Mastrangelo
    Jackson School of Geosciences, University of Texas at Austin, Austin, TX
  • Aaron Averett
    Jackson School of Geosciences, University of Texas at Austin, Austin, TX

Abstract

Mount Bonnell comprises a popular city park with a commanding view overlooking Austin and the impounded Colorado River, thereby presenting evidence for geologic controls across a socioeconomic borderland. This location functions as a worthy Geoheritage site for Central Texas. The Bureau of Economic Geology, which functions as the State Geological Survey of Texas, in partnership with the City of Austin, created a Texas GeoSign here in 2021 (https://www.beg.utexas.edu/geosign). The Bureau also produced a YouTube video about Mt. Bonnell and the Balcones Escarpment with the goal of reaching an off-site audience (https://youtu.be/UtARsaoJ99k). Local media featured stories about the sign, broadening the sign’s reach.

Mount Bonnell occupies the upthrown side of the main fault line within the Balcones Fault Zone in Austin. With a displacement of roughly 200 m, long-term erosion has sculpted the Balcones Escarpment, which extends southwest from Austin through San Antonio and on to the Rio Grande near Del Rio. Although the escarpment is a discontinuous topographic break, it marks the boundary between two grand physiographic provinces of North America: the Great Plains to the west and the Gulf Coastal Plain to the east. This break also extends north to include the buried Ouachita orogenic belt that underlies Temple, Waco, and Dallas–Ft. Worth. The Balcones–Ouachita borderland provides resources of great value to the human economy: prime cropland along the inner reaches of the Coastal Plain; prolific springs near the foot of the escarpment; and rangelands on the upfaulted carbonate rocks where hilly terrain is rapidly being transformed by residential and commercial development. This geo-cultural break marks the boundary of the American West in Texas.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-379534

© Copyright 2022 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.