Late cenozoic displacement transfer in the eastern Sylvania Mountain fault system and Lida Valley pull-apart basin, southwestern Nevada, based on 3D gravity depth inversion and forward models.

摘要

The Sylvania Mountain fault system transfers displacement from the Eastern California shear zone to the Walker Lane as it stretches from the Furnace Creek-Fish Lake Valley fault in southwestern Nevada. Strands of the structure bound the Lida Valley pull-apart basin which, based on gravity analysis, is internally dissected by a system of faults. The subsurface geometry was determined from our gravity survey with data inverted in 3D. Geologic cross-sections were used to forward model the gravity. Mapped faults and inferred structures were combined to construct the subsurface geometry and evaluate a fault displacement budget. By conserving fault slip, the restoration of the pre-Neogene basement to a reference datum indicates a cumulative vertical displacement of 2.3 to 2.5 km since onset of extension. Vertical displacements were used to compute the horizontal component of extension, ranging from 1.3 to 1.4 km.