SEDIMENTARY RECORD OF MARINE AND TERRIGENOUS ORGANIC MATTER DELIVERY TO THE SHATSKY RISE, WESTERN NORTH PACIFIC, OVER THE LAST 130 KYR

Abstract

Biomarker and carbon isotopic analyses of piston core samples were undertaken to reconstruct changes over the last 130 kyr in the delivery of organic matter from marine plankton and terrestrial sources to sediments on the Shatsky Rise in the western North Pacific. Marine and terrigenous organic matter delivery was reconstructed from alkenone and n-alkane concentrations using multiple regression analysis, which gave results consistent with a δ13C mass balance model. Marine organic carbon comprises more than 86% of the total organic carbon throughout the sediment record. Fluxes of marine organic carbon were higher in glacial times, indicating that marine production increased in these periods. We conclude that in addition to the southward shift of the Subarctic front, eolian dust supply at this location played an essential role in enhancing paleoproduction during the last glacial maximum.