At Site 1130, in addition to routine monitoring of hydrocarbon gases for safety, inorganic carbon (IC) analyses were made. The analytical procedures are described in "Organic Geochemistry" in the "Explanatory Notes" chapter.
Concentrations of volatile hydrocarbons were routinely determined in every core from Holes 1130A and 1130C using standard ODP headspace sampling procedures. Only low concentrations of methane were detected; the maximum concentration was 11.3 ppm and most samples have <7 ppm (Table T6). No heavier hydrocarbon gases (C2+) were detected.
Hydrogen sulfide (H2S) was detected in headspace samples from 13 to 126.7 mbsf and was much lower in concentration than at Sites 1127, 1129, and 1131. The maximum concentration (3800 ppmv) was observed at 41.50 mbsf.
Inorganic carbon concentrations were converted to calcium carbonate percentages (see "Organic Geochemistry" in the "Explanatory Notes" chapter). Calcium carbonate content in Hole 1130A ranges from 80.9 to 93.2 wt%, with most samples having 85 to 90 wt% (Table T7; Fig. F15).
Concentrations of methane in the headspace samples at Site 1130 were only slightly above background level.