245 D35. Recent Advances in Structural Geology and Tectonics (Posters)

Wednesday, 12 October 2022
9:00 AM - 1:00 PM
Exhibit Hall F

PALEOSTRESS AND FRACTURE ANALYSIS OF THE EASTERN BIGHORN MOUNTAINS AND WESTERN BLACK HILLS, POWDER RIVER BASIN

Paper number: 245-14
Program: Technical Sessions
Time: 9:00 AM – 1:00 PM

Authors

Abstract

The Powder River Basin is a topographic and structural basin bounded to the west by the Bighorn Mountains in Wyoming and the east by the Black Hills Mountains in South Dakota. In accordance with the Plains CO2 Reduction (PCOR) Partnership, we generated an extensive statewide compilation of existing structural data and collected new measurements on faults, fractures, and veins throughout the Powder River Basin. We collected oriented samples of calcite from veins within host rock Paleozoic limestones and sandstones throughout the Powder River Basin for laboratory analyses. We utilized calcite U-Pb geochronology to constrain the timing of vein emplacement (91.7 ± 4.6 Ma, Bighorn Mountains; 66.0 ± 11.0 Ma and 52.12 ± 0.5 Ma, Black Hills Mountains; 55.7 ± 1.8 Ma, Casper Arch Mountains). We additionally analyzed the samples in thin section for calcite twinning paleopiezometry. This will allow us to interpret both the magnitude and timing of shear stress on the flanks of the Powder River Basin.

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

doi: 10.1130/abs/2022AM-378705

© 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.