Late Pleistocene Sedimentary History of Continental Borderland Basins off Baja California and Southern California: Changes in Terrigenous and Biogenic Sedimentation Rates.

摘要

Analysis of sediment cores yields a record of sedimentary history for the past 35,000 years and includes a complete cold to warm climate cycle. Sedimentation rates have been calculated using open ocean records as a dating tool plus some radiocarbon dates and data from micropaleontologic and oxygen isotopic data. These show that sedimentation rates have varied several fold and that the main effect is exerted by the terrigenous continental input. Pelagic biogenic input has also varied in parallel with the terrigenous contribution but at much lower rates. Organic carbon content parallels carbonate and shows a slight offset in terms of percent of total sediment due to terrigenous dilution and also to rapidity of burial. Slower rates over the past 6000 years have produced lower buried carbon values. Variations appear to be synchronous with the deep ocean record. (Author)