Source:

Morgan, Tony and Linda Scott Cummings
1990   Late Pleistocene and Holocene Paleoenvironmental Conditions in the Lower Santa Ynez River Basin. Proceedings of the Society for California Archaeology 3:243-260.

The climatic reconstructions are based on pollen analyses. The upper timeline is from a study by Heusser (1978) of a sediment core in the Santa Barbara basin. The lower timeline is from Morgan and Cummings' own study in the Santa Ynez River catchment.

The chronologies were originally expressed in radiocarbon years B.P. They have been converted to calendar years here, using Calib 6.0 and estimating midpoints for one-sigma intercepts in the calibrations.

Additional Reference Cited:

Heusser, Linda
1978   Pollen in Santa Barbara Basin, California: A 12,000-year Record. Geological Society of America Bulletin 89:673-678.