Late Pleistocene Holocene Depositional History Of The California Continental Borderland PDF Download

Analysis of the variation in carbonate Contint versus time in sediments from the basins of the California Continental Borderland reveals that the high carbonate sediments correlate with relatively warm water period. This is verified by oxygen isotopic data and micropaleontologic data. In warm times turbidity current contribution is small and the dilution effect of terrigenous sediments is minimal. Conversely, during periods when sediments have low carbonate content the terrigenous sediment rates are high turbidities are common and the influence of local clay sources increases. Examination of the regional patterns of sedimentation shows that the upwelling intensity increased in the area at least two-fold and terrigenous sediment input also increased as much as five-fold during the most recent cold period. It is suggested that this reflects a movement of climatic belts toward the Equator and a concommittant increase in runnoff and upweeling rate. (Author).