Fault Kinematics of the Southern Rio Grande Rift: A Paleostress Analysis

Abstract

Understanding brittle deformation patterns and their sequence of events in southern New Mexico is vital for the discovery and extraction of natural resources. The purpose of this project is to understand the scarcely studied nature and kinematics of faults located within the southern Rio Grande Rift. The region of interest preserves multiple fault populations, most notably NS-trending faults and NW-SE-trending faults. The main hypothesis to test is that, while both fault sets have contributed to extension in the southern Rio Grande rift, the NW-SE-trending faults also preserve evidence for multiple deformation events dating back possibly to the Precambrian era. In order to correlate the existing faults and their kinematics to previously studied tectonic events, a paleostress analysis was performed to determine the orientations of the maximum (σ 1 ) and minimum (σ 3 ) principal stresses of fault populations.