9,000 YEARS OF PALEOHYDROLOGICAL HISTORY INFERRED USING LACUSTRINE SEDIMENTS FROM MADDOX LAKE, CA

California’s well-being depends on the availability of fresh water. Understanding how and why water availability changed in the past is critical for making informed decisions about present and future water management. The objective of this study is to provide a history of hydrologic variability (i.e., lake level) using sediments from a small lake in the northern coast range of California. A 2.6 meter Russian core was collected along the edge of Maddox Lake (88 km west of Redding, CA) in summer 2018. This location was selected to maximize the sediment’s response to changes in lake depth. Age control is based on 10 x AMS C14 dates on discrete organic matter (e.g., charcoal and seeds). An age model was developed using the Bacon program (v2.2), revealing a 9,000 calendar years before present (cy BP; present = 1950 AD) history. The sediments were analyzed for percent water content, dry bulk density, magnetic susceptibility, percent total carbonate, percent total organic matter, and the number of oogonia per gram dry sediment. Initial results reveal large amplitude lake level changes over the past 9,000 cy BP with notable change at 8,500, 7,500, 2,000, and 600 cy BP. Future research will compare these results to lake sites north and south of Maddox Lake to assess the position and strength of California precipitation dipole over the past 9,000 cy BP.