Weathering as a Climate Indicator in Alluvial Systems
Inferring climatic conditions from Earth’s “deep-time” (pre-Cenozoic) geologic record is challenging. Together with my geochemist colleague Dr. Megan Elwood-Madden here at OU, we are devising new ways to read climate from deep time by examining the record of rock weathering in a variety of modern climates by sampling sediments from a wide array of fluvial systems. We have completed sample collections in hot-arid, hot-humid, cold-arid and cold-humid regions, including the desert southwest, Puerto Rico, Antarctica, and Norway. We also ventured closer to home– the Wichita Mountains of Oklahoma. Preliminary results are challenging our views on the way rocks weather under different climatic regimes; owing to the strong connection between rock weathering and atmospheric carbon, these results have implications for understanding how carbon cycles through the Earth system.