Geoscience Australia has recently completed a marine survey in the offshore northern Perth Basin, off Western Australia (Jones et al., 2011b; Jones, 2011c, Upton and Jones, 2011). One of the principal aims of the survey was the collection of evidence for natural hydrocarbon seepage. The survey formed part of a regional reassessment of the basin's petroleum prospectivity in support of frontier exploration acreage Release Area W11-18. This reassessment was initiated under the Australian Government's Offshore Energy Security Program and formed part of Geoscience Australia's continuing efforts to identify a new offshore petroleum province. The offshore northern Perth Basin was identified as a basin with new frontier opportunities. New data demonstrated that proven onshore-nearshore petroleum system is also effective and widespread in the offshore (Jones et al., 2011a). Evidence for a Jurassic petroleum system was also demonstrated in the Release Area W11-18 (Jones et al., 2011a). The marine survey results provide additional support for the presence of an active petroleum system in the northern Perth Basin.

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Tropical cyclones affect storm-dominated sediment transport processes that characterise Holocene shelf deposits in many shelf environments. In this paper, we describe the geomorphology of reef talus deposits found in the Gulf of Carpentaria and Arafura Sea, Australia,that we attribute to tropical cyclones. The orientation of these deposits is also indicative of a consistent, along-coast transport pathway.

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Seagrass communities in the northwest of Torres Strait are known to disappear episodically over broad areas. Sediment mobility surveys were undertaken within two study areas during the monsoon and trade wind seasons, in the vicinity of Turnagain Island, to find out if the migration of bedforms could explain this disappearance. The two study areas covered sand bank and sand dune environments to compare and contrast their migration characteristics. Repeat multibeam sonar surveys were used to measure dune-crest migration during each season.

The Solomon Sea is a semi-enclosed oceanic basin bordered by technically active land masses: its morphology is dominated by an arcuate trough, the New Britain Trench, which bounds the basin on its northern side and is over 8000 metres deep. Density of soundings is sufficient to reveal a large scale left-lateral displacement near the western end of the New Britain Trench; this appears to be a continuation of the onshore Markham-Ramu Lineament. The same structure controls the position of the Markham submarine canyon, which is the major conduit feeding sediment to the ocean basin. No continental shelf is developed along the northern margin of the Huon Gulf owing to the strong and continuing uplift of the Huon Peninsula, which lies within the Northern New Guinea Arc structural province. South of Lae, however, a narrow continental shelf is present. Seismic reflection profiles reveal that this shelf is a geologically young constructional feature, composed in its upper levels of a coalescing series of deltaic deposits. In some areas these can be seen resting directly on non-sedimentary basement. Several submarine canyons cross the shelf and each is closely related to a large river onshore. The seismic records clearly show truncation of strata by the canyon walls: however, it is postulated that upgrowth of the shelf around the canyons, with occasional slumping along the rims, as well as axial downcutting by abrasive sediment flowage, have controlled the formation of the canyons. Their steep axial gradients, which average about 5° compared with the shelf surface which slopes seaward at only 1°, are taken to indicate that the canyons were initiated before the Pleistocene and have maintained their courses during the upward and outward growth of the deltaic deposits forming the present day continental shelf.

This dataset contains processed and raw backscatter data in matlab format produced by the CMST-GA MB Toolbox from various swath surveys in and around Australian waters.

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