Geology Projects

Title: Mineral Analysis of Soda Lake Sediments, California: Implications for the Regional Weathering Evolution

Our previous results from Tulare Lake sediments reveal that the main clay minerals include smectite, illite, chlorite and kaolinite. Smectite is mostly contributed from the Sierra Nevada mountain foot slopes where unleaching environment dominates. Illite is the product of physical wreathing of the granite basement rocks. The variations of abundance ratios of smectite to illite can be used as a proxy to indicate the past climate change in the southern Sierra Nevada. In order to expand our knowledge of the climate change to a large geographic background, we plan to perform mineralogy analysis for samples from the Soda Lake.

In this study, clay-size mineralogy analysis on a suite of 30 lake sediment samples from the Soda Lake will be performed with an X-ray Diffractometer (XRD). The results will be used 1) to observe the clay minerals presents in the sediments as a function of time and to verify the normal trend of weathering; 2) to learn about the changes of climate and environment in the southwestern North America during the formation of the profile studies. Soda Lake is a dry lake that is located in the coastal range area. And it is separated from the Tulare Lake by the coastal ranges. So we expect to see different mineralogy assemblages and temporal variations.