A RECORD OF HOLOCENE PALEOCLIMATE FROM THE SUNDA SHELF, SOUTH CHINA SEA
Two mud-dominated sediment cores were collected from flooded, north-south trending fluvial paleochannels on the inner Sunda shelf north of Bintulu, Sarawak, Malaysia. Given the rarity of planktonic foraminifera in this shallow water (52–63 m water depth), AMS radiocarbon age estimates of the benthic foraminifer Cavarotalia annectens provide age control for the cores. A total of 19 samples, spaced 20 cm apart, were dated in core D42. This core, 3.8 meters in length, yields a detailed record of over 3000 years. Fifteen samples, ca. 16 cm apart, were dated in core D45, 2.6 meters in length. This core, collected from a slightly deeper location on the shelf, provides a record of over 7000 years. Contiguous, 2 cm samples provide a ca. 20-year resolution in D42 and a ca. 50-year resolution in D45. Mg/Ca ratios, δ13C and δ18O of planktonic foraminifera (Globigerinoides spp.) are being analyzed to define variations in sea surface temperature, salinity, and nutrients. These factors are related to changes in precipitation and runoff and thus provide information on past characteristics of the EAM.