Geoscience Australia marine reconnaissance survey TAN0713 to the Lord Howe Rise offshore eastern Australia was completed as part of the Federal Government's Offshore Energy Security Program between 7 October and 22 November 2007 using the New Zealand Government's research vessel Tangaroa. The survey was designed to sample key, deep-sea environments on the east Australian margin (a relatively poorly-studied shelf region in terms of sedimentology and benthic habitats) to better define the Capel and Faust basins, which are two major sedimentary basins beneath the Lord Howe Rise. Samples recovered on the survey contribute to a better understanding of the geology of the basins and assist with an appraisal of their petroleum potential. They also add to the inventory of baseline data on deep-sea sediments in Australia. The principal scientific objectives of the survey were to: (1) characterise the physical properties of the seabed associated with the Capel and Faust basins and Gifford Guyot; (2) investigate the geological history of the Capel and Faust basins from a geophysical and geological perspective; and (3) characterise the abiotic and biotic relationships on an offshore submerged plateau, a seamount, and locations where fluid escape features were evident. This dataset comprises chlorin indices measured on seabed sediments (0-2 cm). Some relevant publications which pertain to these datasets include: 1. Heap, A.D., Hughes, M., Anderson, T., Nichol, S., Hashimoto, T., Daniell, J., Przeslawski, R., Payne, D., Radke, L., and Shipboard Party, (2009). Seabed Environments and Subsurface Geology of the Capel and Faust basins and Gifford Guyot, Eastern Australia - post survey report. Geoscience Australia, Record 2009/22, 166pp. 2. Radke, L.C. Heap, A.D., Douglas, G., Nichol, S., Trafford, J., Li, J., and Przeslawski, R. 2011. A geochemical characterization of deep-sea floor sediments of the northern Lord Howe Rise. Deep Sea Research II 58: 909-921

A document briefly describing levelled ship-track gravity and magnetic data available for download from the Geophysical Archive Data Delivery System (GADDS) that cover the southwest margin of Australia in the region enclosing 106-120°E and 19-37°S. The document will be provided whenever the data are downloaded from GADDS. Note that the data is archived on the Corporate Data Store

During April/ May 1988 the Bureau of Mineral Resources will conduct a 22 day geochemical research programme in the Otway and Gippsland Basins. This programme follows previous preliminary studies (January-February 1987) which examined the distribution and molecular composition of light hydrocarbon gases within deep water surficial sediments in the Otway Basin.The major thrust of the forthcoming cruise will be to obtain shallow water (continental shelf) geochemical data from both the Otway and Gippsland Basins, to test ideas generated from the previous programme, and, inparticular, to integrate the results with in house BMR geohistory and maturation modelling studies. The objectives are, therefore: 1.To develop new information on source rocks, maturation, and hydrocarbon migration on the Mussel and Crayfish Platforms and Voluta Trough in the Otway Basin. 2.Specifically, to test the relationship between variations in sourcerock maturation (as indicated by well data and geohistory analyses) andthe surface hydrocarbon gas composition and distribution within sediments from the Otway and Gippsland Basins. The majority of the programme will be focussed on the Otway Basin, with the final 4-5 days of the cruise spent in the Gippsland Basin. Sampling will becarried out along previously shot BMR multi-channel seismic lines, and will consist of vibracoring in shallow water (<150m) and combinations of piston and gravity coring in deeper water. In the Otway Basin, four key profiles will be sampled (see Fig.1). The two western profiles (A & B) run from the Crayfish Platform into the VolultaTrough, whereas the eastern profiles (C & D) run from the Mussel Platform into the central Voluta Trough. On all of these profiles the basal Early Cretaceous, considered the section with the best source potential, becomes progressively deeper buried (towards A" etc.), with maturity increasing from VR =1.0-1.3 (peak oil generation) on the Platform margins to over mature (VR = 3.0-4.0) in the central Voluta Trough. Similarly, the Late Cretaceous sequences (eg. Belfast Mudstone), which are immature on the Platform margins, are ideally placed within the oil window in the central Voluta Trough. The molecular compositions of the thermogenic gases withinthe surface sediments along these profiles may thus provide important cluesto the nature of the principal source horizons within the Otway Basin. For example, a dry gas signature in the central Voluta Trough would argue against a Late Cretaceous source, and support the contention that the Early Cretaceous is the major source horizon. In addition to the above profiles, specific areas will be studied indetail. These include previously defined hydrocarbon anomalies andpotential seafloor seeps off Port Douglas (see Fig.1). The Gippsland Basin programme will consist principally of sampling from the southern shelf, through the Central Deep, and onto the Lakes Entrance Platform (see Fig.2). Latrobe Group source rocks vary from immature toovermature along this transect, and the objective is to determine whetherthis change in maturity is reflected in the composition of the surface hydrocarbon gases. The Gippsland programme will allow a comparison of theresults obtained from a frontier exploration area, the Otway Basin, withthose from a major oil/gas producing province. In both the Otway and Gippsland Basins, high resolution seismic data willbe collected over selected hydrocarbon anomalies, in order to better definenear-surface structure, particularly faulting. This data will be acquiredwith either a 15 or 80 cubic inch water gun.

Legacy product - no abstract available

Since 1985 the Bureau of Mineral Resources (BMR) has been involved in three coring cruises off southwest Victoria and Tasmania. A great amount of laboratory work has been done on the cores, generally on samples taken at 20cm intervals, by technicians in BMR's Division of Marine Geosciences and Petroleum Geology, and the aim of this record is to document the results. The analytical work has been designed to be complementary to other scientific studies on the cores: physical descriptions, smear slide descriptions, and palaeontological examinations. The aim of all the work has been to adequately describe the variations which have taken place with time in the cores, and to relate these back to regional and local changes in depositional environment. The final intention of the studies is to build up a model of sedimentation on the continental margin which, in conjunction with reflection seismic data, can be used to interpret depositional packages in much older sequences. The first sampling cruise was carried out in early 1985, aboard the West German research vessel Sonne (S0-36C) in a co-operative venture between BGR (German Geological Survey) and BMR. This survey took 43 cores off west Tasmania and on the South Tasman Rise (Figures 1B and 2) These cores varied in length from 0.55m to 7.78m (Table 1),and full station data are given in Hinz et al. (1985). Bolton et al. (1988)described six cores from the South Tasman Rise containing ferro manganese crust and nodules. Grainsize and CaCO3 analyses for 9 Sonne cores are presented in this Record. The second sampling cruise, BMR Cruise 67, was carried out by BMR's research vessel Rig Seismic in 1987, off southwest Victoria and western Tasmania (Figures lA and 3). This survey took 54 cores varying in length from 0.10m to 3.64m (Table 2), and full station data are given in Exon, Lee et al. (1987) and Exon, Lee et al. (1989). Grainsize and CaCO3 analyses on 35 cores carried out at BMR are reported here, as well as TOC (Total Organic Carbon %) and CaCO3 analyses from low in 15 cores carried out by AMDEL. The third sampling cruise, BMR Cruise 78, was carried out by Rig Seismic in 1988, off western Tasmania (Figures 4 and 5). Altogether 38 core stations were occupied, of which 22 were successful. Core recovery varied from 0.02m to 7.33m (Table 3) and full station data will be given in Exon, Lee and Hill (1989). Grainsize and CaCO3 analyses from 10 cores are reported here.

R/V Rig Seismic carried out Bureau of Mineral Resources (BMR) research cruise 78 on the Tasmanian margin from 24 March to 18 April, 1988. The first half of the cruise was devoted to multichannel seismic surveying - 1750 km on the west Tasmanian margin and 265 km off southeast Tasmania. The west Tasmanian seismic survey examined the King Island and Strahan Sub-basins of the Sorell Basin, tested the structure of the continental margin from the continental shelf to undoubted oceaniccrust, and provided a key seismic tie through the thick sedimentary basin on the west Tasmanian continental slope. The southeast Tasmanian seismic survey examined the Palaeozoic sequences near Bruny Island on which oil seeps are known. The latter half of the cruise was devoted to geological sampling on the west Tasmanian margin. Twelve stations were designed to sample basement and older outcropping sequences (Mesozoic and Palaeogene) to provide control for seismic interpretation. Younger sequences were cored at 37 stations in order firstly, to establish amodel for Cainozoic sedimentation, and secondly, to allow the analysis of surface sediments to define areas of anomalous concentrations of thermogenic gas. Near-surface thermal gradient and thermal conductivity were measured at 10 stations as a means of establishing thermal flux. The work will enable us to better define the geology of the basins, and especially their history of rifting, their stratigraphy, and their petroleum potential.

Legacy product - no abstract available

The purpose of this report is to summarise the processing techniques applied to the non-seismic geophysical data collected on BMR Marine Survey68, northeast Gippsland Basin and southern New South Wales margin. The cruise was conducted between 21 March and 15 April 1987.

Legacy product - no abstract available

Legacy product - no abstract available