Latest Pleistocene through Holocene Lake Levels from the TL05-4 Cores, Tulare Lake, CA, U.S.A.: constrained by the Smear Slide Technique

• Main Author: Padilla, Kelsey A
• Other Authors: Negrini, Robert, Krugh, William C., Guo, Junhua
• Format: Master Thesis
• Language: English
• Published: California State University, Bakersfield 2015
• Subjects: Holocene Geologic Period; California > Tulare Lake Region; Pleistocene Geologic Epoch; Lake sediments; Low Lake; Pacific; Ice cap
• Online Access: https://hdl.handle.net/20.500.12680/2227ms92z

Lake sediments are often associated with high deposition rates, thus offering a detailed repository of lake level, climate, and the terrestrial environment surrounding the lake. Prior to diversion of stream flow for the purpose of irrigation, Tulare Lake was the largest fresh water lake west of the Great Lakes (Preston, 1981). At that time, its lake level was predictably related to the discharge of four Sierran streams, the Kern, Tule, Kaweah, and Kings Rivers, and can therefore be used as the basis for temporal river discharge reconstruction by locating and dating the past surface elevations of Tulare Lake (Atwater et al., 1986). This will ultimately lead to improved forecasting for Sierran discharge over the next several decades after this record is compared to improving coeval records of sea-surface temperatures of the Pacific Ocean. The core-based, lake-level proxy record of Blunt (2013) for Tulare Lake, CA suggests deep lake and wet conditions during the early Holocene, dry low lake conditions throughout the mid-Holocene, and a return to wet and deeper lake conditions during the late-Holocene. The assertion is made that Tulare Lake levels are reflective of regional climate rather than local geomorphology. This study uses the smear slide technique of Schnurrenberger et al. (2003) to test the findings of Blunt (2013). The resultant geobiological and granular results are generally consistent with the predictions of Blunt (2013). At the lower end of the record, the interval hypothesized to contain sand-sized grains of Tioagan-aged glacial outwash from the Sierra Nevada ice cap, have, as predicted, little to no organic matter or carbonate present and are characterized by sand grains of granitic composition typical of the source stream headwater geology. The concentration of phytoliths, specifically grass tracers, are consistent throughout the core with levels of previously documented intervals of high clay percent in the early Holocene, supporting the argument that this proxy for high lake levels is a signal of ...