Sediments from five Leg 167 drill sites and three piston cores were analyzed for Corg and CaCO3. 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 CaCO3 and Corg time series. We show that the CaCO3 events are caused by changes in CaCO3 production by plankton, not by dissolution. We also show that these CaCO3 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 CaCO3 production and burial occurs when the surface ocean is somewhat cooler than the modern ocean, and the surface mixed layer is somewhat more stable.
1Lyle, M., Koizumi, I., Richter, C., and Moore, T.C., Jr. (Eds.), 2000. Proc. ODP, Sci. Results, 167 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/167_SR/167sr.htm>. [Cited YYYY-MM-DD]
2Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, Boise ID 83725, USA. Correspondence author: mlyle@cgiss.boisestate.edu
3College of Ocean and Atmospheric Science, Oregon State University, Corvallis OR 97331, USA.
4Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz CA 95064, USA.
5Lamont-Doherty Geological Observatory, Columbia University, Palisades NY 10987, USA. (Present address: Heusser and Heusser, Inc., 100 Clinton Road, Tuxedo NY 10987, USA.)
Date of
initial receipt: 15 October 1998
Date of acceptance: 10 May 1999
Ms 167SR-214