At Sites 1110, 1111, and 1112, the shipboard organic geochemistry consisted of determinations of total organic carbon (TOC), inorganic carbon, total carbon, total nitrogen, and total sulfur in sediments, in addition to the routine hydrocarbon gas safety monitoring procedure. No samples were collected at Site 1113. The analytical techniques used are outlined in "Organic Geochemistry" in the "Explanatory Notes" chapter.
Because of poor core recovery, very little data was collected at all of the sites. At Sites 1110 and 1112, methane concentrations were found to be low (<6 ppmv) at the surface, increasing to 35 ppmv by 69 mbsf at Site 1112 (Table T12; Fig. F24). Low methane concentrations (~3-32 ppmv) were generally found between 0 and 117 mbsf at Site 1111 (Table T12; Fig. F24) but showed a thousandfold increase between 117 and 127 mbsf. This correlates with the disappearance of sulfate in the pore waters at this depth (see Table T11 and "Inorganic Geochemistry") and is indicative of the start of bacterial methane production. No other hydrocarbon gases were detected at any of the sites.
The CaCO3 concentrations are given in Table T13. Organic carbon was found to be low at all the sites, and no nitrogen or sulfur was detected in any of the sediment samples (Table T13).