Magnitude of right-lateral offset on the southern Death Valley fault zone from Miocene volcanic assemblages

In this study correlation of Miocene volcanic and sedimentary rocks in southern Death Valley is used to constrain the total amount of slip on the southern Death Valley fault. The tertiary volcanic section near Ibex Pass is correlated to rocks &sim35 km to the northwest, in the Wingate Wash region (Luckow et al., 2005). Geochronology by Luckow et al. (2005) in Wingate Wash and the Owlshead Mountains has the region divided into two basic periods: an early interval (&sim14-13.4Ma), and a later phase (&sim13-12.5Ma). One date from the volcanic sequence in Ibex Pass has been reported (Calzia, 2000) suggesting that rocks of this section is a time equivalent to the Wingate Wash section. However, Topping (1993) suggested this section contains the &sim10 Ma Rhodes tuff, and is therefore is at least partially distinctly younger than the Wingate Wash section. Geochemical analyses and geologic mapping of lithologic units in Ibex Pass was performed to determine the structure and magmatic history of the area. Results from the correlation of physical stratigraphy and elemental chemistry on volcanics in southern Death Valley, suggests a geologic association between Wingate Wash and Ibex Pass. Data provided on the Pre-Shoshone volcanics containing the Rhodes Tuff was determined to have no stratigraphic or geochemical connection to the Ibex Pass volcanics. The data on the rock units in Ibex Pass clarifies the age discrepancy given for this region as well. The research conducted provides a better understanding on the displacement that has occurred in the southern Death Valley right-lateral strike slip system. The correlation of volcanic and sedimentary rocks along the southern Death Valley fault zone demonstrates there is at least &sim25km of slip and as much as &sim35km of slip that has occurred along the fault zone in the last 12Ma. A reconstruction model created for this study displays the suggested amounts of offset.