Holocene depositional history inferred from single-grain luminescence ages in southern California, North America

Significant sediment flux and deposition in a sedimentary system are influenced by climate changes, tectonics, lithology, and the sedimentary system's internal dynamics. Identifying the timing of depositional periods from stratigraphic records is a first step to critically evaluate the controls of sediment flux and deposition. Here, we show that ages of single-grain K-feldspar luminescence subpopulations may provide information on the timing of previous major depositional periods. We analyzed 754 K-feldspar single-grains from 17 samples from the surface to ∼9 m-depth in a trench located downstream of the Mission Creek catchment. Single-grain luminescence subpopulation ages significantly overlap at least eight times since ∼12.0 ka indicating a common depositional history. These depositional periods correspond reasonably well with the Holocene intervals of wetter than average climate conditions based on hydroclimatic proxies from nearby locations. Our findings imply a first-order climatic control on sediment depositional history in southern California on a millennial timescale.