(Table 1) Geochemistry of sediment core NS93-5

The biogenic-related elements Ca, Sr, Ba, P, Cd, scavenged Al, and Ti were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) for Core NS93-5 from the west slope of the South China Sea. Terrestrial input as estimated from the accumulation of Ti was higher during glacials than during interglacials. Carbonate accumulation rates are inversely related to those of terrestrial input, suggesting higher production of calcareous phytoplankton during interglacials. The accumulation patterns of authigenic Sr, Ba, P, and Cd match that of carbonate, further indicating higher calcareous phytoplankton production during interglacials. Scavenged Al and excess SiO2, which is related to biogenic opal, exhibit higher accumulation rates during glacials and correspond with changes in terrestrial input. This indicates that terrestrial input driven is important to siliceous phytoplankton production but not for calcareous phytoplankton production. As calcareous phytoplankton is the dominant component of the biogenic sediments in the South China Sea, particularly during interglacials, previous inference of higher productivity in the South China Sea during glacials based on only the biogenic opal proxy needs to be reconsidered.

(Table 1) Downhole variation of potassium, apparent K-Ar age, and inert gas abundances at DSDP Holes 69-504B, 70-504B and 83-504B

Ne, Ar, Kr, Xe, and K2O were measured in representative samples of holocrystalline basalt from DSDP Hole 504B. No hiatus in inert gas abundance is recognized at the base of the "oxic" alteration zone and the extent rather than the nature of alteration appears to determine these abundances. When the inert gas abundances are separately plotted against K2O, two distinct trends of loss emerge, one for alteration involving K-gain, the other for K-loss. Apparent whole-rock K-Ar ages are anomalous in the upper 50 m of basement, and below 300 m sub-basement. In the intervening zone of basement, celadonization adds sufficient potassium and eliminates enough "primary" 40Ar early in the history of the basalts for "excess" 40Ar to become subordinate to radiogenic 40Ar in basalts showing potassium enrichment greater than 0.2%. Stratigraphically correct K-Ar ages are obtained, therefore, from K-enriched basalts of the oxic alteration zone.