REE, Ba, and Sr abundances and Sr, Nd, and Ce isotope ratos of ODP Hole 110-504B basalts

Abundances of rare earth elements (REE), Ba, and Sr and isotopic ratios of Sr, Nd, and Ce were determined for six samples of basalts drilled at Hole 504B on Leg 111 of the Ocean Drilling Program. Analyses found that these basalts are the most depleted in Sr, Ba, and light REE among mid-ocean ridge basalts (MORB); Ba depletion is especially notable. On the other hand, Sr, Nd, and Ce isotopic ratios for basalts from Hole 504B are within the range of typical MORB values.

Bulk chemical analysis of sediments ODP Hole 110-671B and 110-672A

Chemical analyses for calcium carbonate, organic carbon, and major constituents (Al, Ti, Ca, Mg, K, Fe) of bulk sediments collected in Hole 671B have been carried out. Organic carbon contents in Pleistocene through middle Miocene sediments above the zone of decollement are very low (<0.1%); below the decollement considerably higher concentrations of organic carbon occur (up to 1 %). Changes in Ti/Al and Fe/Al ratios are minor, but K/Al and Mg/Al ratios show clear trends with the age of the sediments. Preliminary comparisons of these ratios with mineralogic information on clays indicate good correspondence with clay abundances. Calculations of the mass flux of magnesium from the overlying ocean into the pore fluids suggest that addition of magnesium to the sediments is difficult to detect, especially in the absence of a background reference concentration.