Seafloor environments of the eastern Timor Sea, Northern Australia: Inorganic chemistry of seabed sediments.

Brief description

The Timor Sea and its tropical marine environment support significant and growing economic activity including oil and gas exploration. To reduce uncertainty in decision making regarding the sustainable use and ongoing protection of these marine resources, environmental managers and resource users require sound scientific information on the composition and stability of seabed environments and their biological assemblages. Surveys SOL4934 and SOL5117 to the eastern Joseph Bonaparte Gulf were undertaken in August and September 2009 and July and August 2010 respectively, in collaboration with the Australian Institute of Marine Science, with research collaborations from the RAN Australian Hydrographic Office, the Geological Survey of Canada and the Museum and Art Gallery of the Northern Territory. The purpose of these surveys were to develop biophysical maps, and deliver data and information products pertaining to complex seabed environment of the Van Diemen Rise and identify potential geohazards and unique, sensitive environments that relate to offshore infrastructure. This dataset comprises inorganic chemistry of seabed sediments (0-2cm). Some relevant publications are listed below: 1. Heap, A.D., Przeslawski, R., Radke, L., Trafford, J., Battershill, C. and Shipboard Party. 2010. Seabed environments of the eastern Joseph Bonaparte Gulf, Northern Australia: SOL4934 Post Survey Report. Geoscience Australia Record 2010/09, pp.81. 2. Anderson, T.J., Nichol, S., Radke, L., Heap, A.D., Battershill, C., Hughes, M., Siwabessy, P.J., Barrie, V., Alvarez de Glasby, B., Tran, M., Daniell, J. & Shipboard Party, 2011b. Seabed Environments of the Eastern Joseph Bonaparte Gulf, Northern Australia: GA0325/Sol5117 - Post-Survey Report. Geoscience Australia, Record 2011/08, 58pp. 3. Radke, L.C., Li, J., Douglas, G., Przeslawski, R., Nichol, S, Siwabessy, J., Huang, Z., Trafford, J., Watson, T. and Whiteway, T. Characterising sediments of a tropical sediment-starved continental shelf using cluster analysis of physical and geochemical variables. Environmental Chemistry, in press

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Maintenance and Update Frequency: asNeeded

Statement: Surface sediments were collected using either a shipek grab or a Smith McIntyre grab. The surface sediments (0-2 cm) within the grab were spooned into falcon vials and the porewaters were removed by centrifugation. The samples were then frozen for transport to the laboratories at Geoscience Australia (GA) where they were freeze-dried and ground in a tungsten carbide mill. Major and trace elements were determined by X-ray fluorescence at GA using a Phillips PW204 4kW sequential spectrometer. A more comprehensive suite of trace elements was determined using a AGILENT 7500ce ICP-MS, also at GA. The attribute accuracies are moderate: <5% for majors and <10% for trace elements. Thanks to the crew of the RV Solander for help with sample collection.