A summary of shipboard Rock-Eval measurements shows that organic matter in Upper Triassic siltstone from the Wombat Plateau is dominated by Type III kerogen and is thermally immature. Neocomian siltstone from the Exmouth Plateau similarly contain thermally immature Type III organic matter. Overlying Upper Cretaceous to Quaternary carbonates are poor in organic matter at both locations, yet significant amounts of methane-dominated gas are dissolved in the pore waters of the thick carbonate sequence present on the Exmouth Plateau. This dry gas is believed to have migrated from deeper and more mature strata containing Type III kerogen.

Sediment depth is given in mbsf. Vitrinite reflectance measurements (%Ro) made by W. Kalkreuth at the Geological Survey of Canada.

Supplement to: Snowdon, Lloyd R; Meyers, Philip A (1992): Source and maturity of organic matter in sediments and rocks from Sites 759, 760, 761, and 764 (Wombat Plateau) and Sites 762 and 763 (Exmouth Plateau). In: von Rad, U; Haq, BU; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 122, 309-315