Millennial-scale CaCO3 and Corg events along the northern and central California margins: stratigraphy and origins [chapter]

M. Lyle, A. Mix, A.C. Ravelo, D. Andreasen, L. Heusser, A. Olivarez
2000 Proceedings of the Ocean Drilling Program  
Sediments from five Leg 167 drill sites and three piston cores were analyzed for C org and CaCO 3 . Oxygen isotope stratigraphy on benthic foraminifers was used to assign age models to these sedimentary records. We find that the northern and central California margin is characterized by k.y.-scale events that can be found in both the CaCO 3 and C org time series. We show that the CaCO 3 events are caused by changes in CaCO 3 production by plankton, not by dissolution. We also show that these
more » ... O 3 events occur in marine isotope Stages (MIS) 2, 3, and 4 during Dansgaard/Oeschger interstadials. They occur most strongly, however, on the MIS 5/4 glaciation and MIS 2/1 deglaciation. We believe that the link between the northeastern Pacific Ocean and North Atlantic is primarily transmitted by the atmosphere, not the ocean. Highest CaCO 3 production and burial occurs when the surface ocean is somewhat cooler than the modern ocean, and the surface mixed layer is somewhat more stable.
doi:10.2973/ fatcat:6mgb6mcwfrdn7f4a6umt7vvarq