UC Riverside

The fossil record of lake strata typically provide a high resolution record of past ecosystems and environmental conditions. The faunal records of the Pliocene Waucobi Lake beds provide such an opportunity to interpret environmental and climate conditions for the eastern Sierra Nevada. These lacustrine sediments cropping out in Soldier Canyon, Owens Valley, Inyo County, CA are composed primarily of clay beds with several freshwater species of ostracodes and gastropods. These presence and absence of key taxa and the relative abundance of various gastropod and ostracode taxa for the Sierra Nevada during the late Pliocene demonstrate that there were changes in salinity in the Waucobi Lake associated with an open- and closed-basin lake system, driven by the Sierra Nevada rainshadow climate control. Lake beds containing gastropods were interpreted as freshwater events. In this study two sections were stratigraphically analyzed for fossil ostracode and gastropod variability. The high resolution sampling revealed the presence of ostracode assemblages suggests interruptions of saline conditions occurred more frequently than previous reported.