INFLUENCE OF TECTONICS ON MIO-PLIOCENE DRAINAGE DEVELOPMENT IN THE DEATH VALLEY REGION

Endemic species of fish and snails in Amargosa Valley, Death Valley, and Owens Valley springs are isolated today, but share a common Pliocene ancestor. This suggests that a hydrological system that once connected these regions was fragmented, allowing for the continuing separate evolution of the species in the three valleys. Here we use dynamic tectonic-landscape evolution models to study whether a hydrological system fragmented by tectonic events could explain the species diversification.

The tectonic reconstructions by Lutz et al. (GSA abstract in this session) are used as input to forward model drainages in the study area. We use an updated version of the tectonic-landscape evolution model TISC (Tectonics, Isostasy, Surface Processes, and Climate; Garcia-Castellanos, 2002; Berry et al., 2019). With TISC, tectonics are simulated kinematically (allowing us to use tectonic reconstructions of the study area), and the model can handle the formation of lakes and endorheic conditions in extensional tectonic settings. In this presentation we discuss our modeling approach, including tectonic simplifications, and climate, and show preliminary results.