GEOMETRIC AND KINEMATIC ANALYSIS OF THE CHICKEN SPRINGS FAULT SYSTEM, A DIFFUSE HOLOCENE FAULT SYSTEM IN THE GREAT DIVIDE BASIN, WYOMING

The Chicken Springs fault system is a system of multiple east-west trending fault scarps in Quaternary sediments (mostly residuum of the Eocene Battle Spring formation) that have throws ranging from 0.5 – 4 m. Previous research on this system is limited, mostly consisting of reconnaissance investigations and 1:24,000 surface mapping. Regardless of the apparent youthfulness of these fault scarps, they pose little seismogenic hazard due to the remoteness of these faults and sparse infrastructure in this part of Wyoming, and thus have not prompted significant previous investigations. Despite this, these faults constitute a peculiar intraplate fault system with no readily apparent structural source mechanism and warrant further investigation. Some possible mechanisms include “moment-bending” faulting above a cryptic growing fault / fold system, stress localization effects from the subsurface geology, a reactivated Mesozoic / Cenozoic fault complex, and reconfiguration of the regional stress field in the late Pleistocene / Holocene.

To investigate the evolution and structural geology of the Chicken Springs fault system, we have started by acquiring high-resolution sUAS imagery of a transect crossing a central portion of the fault system. These were processed into a point cloud, which could then have topographic profiles extracted and analyzed. There are nine fault scarps within the extent of this dataset. Due to their location in a consistent weathered material, fault degradation (diffusion) analysis should offer a useful first-order estimate of the timeframes and slip rates that may have occurred on these faults. These results should guide future efforts that would include shallow seismic reflection / refraction, integration with deep industry seismic data, and geochronology to better refine the timing and structural context of these faults.