Tom Schweich  

Rex Hills

The Stateline fault system is a dextral strikeslip fault that, between latitudes 35°N and 37°N, probably forms the eastern limit of the eastern California shear zone–southern Walker Lane belt. The Rex Hills study site lies along a transpressional left-bend between the Pahrump and Amargosa segments of the Stateline fault system where the central part of the Stateline fault system crosses from Stewart Valley into southern Amargosa Valley. The Rex Hills are two small connected hills: the NW hill is 40 m high and has a dome shape with a diameter of ~900 m; the SE hill is 45 m high, boat-hull shaped, and ~1500 m long by ~750 m wide. The Rex Hills fault pattern exhibits a reverse and a dextral strike-slip component. The dextral component is expressed as drainage offsets with a magnitude of up to ~10 m, commonly associated with zones of highly fractured clasts within the Plio-Pleistocene conglomerate that show dextral sense of shear. The thrust component is expressed as 0.3- to 2-m high fault scarps.