Subsamples were divided for coarse-fraction and geochemical analyses. For the coarse fraction, weighed freeze-dried samples were soaked in deionized distilled water and then washed through 63-µm sieves. The >63-µm fraction residue was collected, dried, and weighed. The weight of the >63-µm fraction divided by the weight of the original sample gives the coarse fraction in weight percentage (wt%). In the analyses of calcium carbonate and total organic carbon (TOC) concentrations, dried bulk sediment was first ground to a powder and then two weighed samples (~0.1 g) were measured using a LECO CS-244 carbon/sulfur analyzer. One of the two weighed samples was directly measured for total carbon (TC) content. The procedure involves heating the sample at 850°C and measuring the combustion products by infrared energy detector. The other sample was digested with 2.4-N HCl to remove carbonates. The carbonate-free residue was washed thoroughly with deionized distilled water and dried, and then the residual carbon was measured. This value represents the TOC content of the sediment. The difference between the two carbon measurements (TC - TOC) gives the total inorganic carbon (TIC) content. CaCO3 concentration is calculated by
assuming all inorganic carbon is present as calcite or aragonite. Precision of the analyses is better than 0.04% and 0.10% for working standard (bulk sediments from the SCS) and sediment samples, respectively (Table T1). The method used here is different from that used on board the JOIDES Resolution but yields comparable results.