Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

268 PATA Days 2024 Contemporary extensional strain accumulation measured geodetically across the central Basin and Range is ~1 mm/yr (Hammond et al., 2014). This rate largely agrees with cumulative rates of strain release by active faulting determined in several paleoseismic transects across the region (Personious et al., 2017; Koehler and Wesnousky, 2011; Wesnousky et al., 2005). Although the Buffalo Valley fault occurs within the general area of these transects, it has not previously been the subject of detailed paleoseismic study, particularly geologic constraints on its slip rate have not been developed. Slip rates are important input parameters for constraining deformation models, such as the 2023 update of the U.S. National Seismic Hazards Model (NSHM) (Petersen et al., 2024; Hatem et al., 2022a) and local probabilistic seismic hazards analyses (PSHA) (Valentini et al., 2020). The NSHM asigns the Buffalo Valley fault a preferred slip rate of 0.1 mm/yr, however, this rate was based on evaluation of a suite of uncertainty distributions derived from broad slip rate categories benchmarked by geodetic strain rates (Hatem et al., 2022b) and not direct geologic observations. Slip rate and recency of faulting are also important modelling input parameters for assessing potential geothermal energy exploration targets. Specifically, these parameters when combined with other geophysical datasets can inform the potential occurrence of blind geothermal systems (Ayling et al., 2022; Faulds et al. 2016). The intersection of the Buffalo Valley fault with the Jersey Valley fault to the south has been characterized as a structural accommodation zone, a favorable structural setting for potential geothermal energy exploration (Burgess & Faulds, 2023; Faulds et al., 2021). Thus, motivated by a need to refine the geologic slip rate of the Buffalo Valley fault for seismic hazard and geothermal energy resource applications, we conducted office and field based fault trace mapping on recently acquired lidar hillshade base maps, produced topographic profiles across faulted deposits to assess the amount of displacement, and described and sampled soil pits excavated on the footwall of the fault to evaluate the relative and absolute ages of displaced surfaces. Fig. 2: Field photographs showing (A) prominent tectonic geomorphology along the southern Buffalo Valley fault range front, and (B) an ~4-m-high scarp extending across an alluvial fan at the location of soil pit 2 (See Fig. 3 for location). Black arrow points to fault in both images.