The measurement of the concentrations and molecular compositions of light hydrocarbon gases within the water column overlying offshore sedimentary basins can provide, under suitable circumstances, significant information on hydrocarbon source rock maturity and/or type, and the most likely locations for petroleum accumulation within basins. These measurements are usually made using a hydrocarbon 'sniffer', which comprises a submersible fish which is towed near the seafloor, and from which water is pumped to the surface and continuously analysed via gas chromatography. Compared with overseas, relatively few 'sniffer' surveys have been carried out around Australia, and hence the applicability and usefullness of this technique to the Australian situation is as yet undetermined.
As a continuation of its geochemical research program, the Division of Marine Geosciences and Petroleum Geology (Australian Bureau of Mineral Resources) will conduct a co-operative geochemical research survey withTransglobal Exploration and Geoscience (TEG) of Leucadia, California, USA, in southeastern Australia between February 1 and March 2, 1989. The cruise will be of 30 days duration and will involve work in the Gippsland, Bass, Otway and Stansbury Basins and the Torquay Sub-basin. A detailed proprietary program will be carried out in the Bass and Stansbury Basins in co-operation with Amoco Production Company. Two regional lines will be run from the Torquay Sub-basin, across the Cape Otway-King Island High, to the Crayfish Platform in the west of the Otway Basin (see Fig. 2). Regional lines will also be run in the Gippsland Basin, with an additional detailed program over several known oil and/or gas accumulations. In addition to the water column geochemistry, a limited sampling program will investigate the light hydrocarbon geochemistry of sediments over known oil and gas fieldsin the Gippsland Basin.
