Geoscience Australia undertook a marine survey of the Vlaming Sub-basin in March and April 2012 to provide seabed and shallow geological information to support an assessment of the CO2 storage potential of this sedimentary basin. The survey was undertaken under the Australian Government's National CO2 Infrastructure Plan (NCIP) to help identify sites suitable for the long term storage of CO2 within reasonable distances of major sources of CO2 emissions. The Vlaming Sub-basin is located offshore from Perth, Western Australia, and was previously identified by the Carbon Storage Taskforce (2009) as potentially highly suitable for CO2 storage. The principal aim of the Vlaming Sub-basin marine survey (GA survey number GA334) was to look for evidence of any past or current gas or fluid seepage at the seabed, and to determine whether these features are related to structures (e.g. faults) in the Vlaming Sub-basin that may extend up to the seabed. The survey also mapped seabed habitats and biota in the areas of interest to provide information on communities and biophysical features that may be associated with seepage. This research addresses key questions on the potential for containment of CO2 in the Early Cretaceous Gage Sandstone (the basin's proposed CO2 storage unit) and the regional integrity of the South Perth Shale (the seal unit that overlies the Gage Sandstone). This dataset comprises bulk organic carbon and nitrogen isotopes and concentrations from seabed sediments (0-2 cm).

Geoscience Australia undertook a marine survey of the Vlaming Sub-basin in March and April 2012 to provide seabed and shallow geological information to support an assessment of the CO2 storage potential of this sedimentary basin. The survey was undertaken under the Australian Government's National CO2 Infrastructure Plan (NCIP) to help identify sites suitable for the long term storage of CO2 within reasonable distances of major sources of CO2 emissions. The Vlaming Sub-basin is located offshore from Perth, Western Australia, and was previously identified by the Carbon Storage Taskforce (2009) as potentially highly suitable for CO2 storage. The principal aim of the Vlaming Sub-basin marine survey (GA survey number GA334) was to look for evidence of any past or current gas or fluid seepage at the seabed, and to determine whether these features are related to structures (e.g. faults) in the Vlaming Sub-basin that may extend up to the seabed. The survey also mapped seabed habitats and biota in the areas of interest to provide information on communities and biophysical features that may be associated with seepage. This research addresses key questions on the potential for containment of CO2 in the Early Cretaceous Gage Sandstone (the basin's proposed CO2 storage unit) and the regional integrity of the South Perth Shale (the seal unit that overlies the Gage Sandstone). This dataset comprises a suite of major and minor inorganic elements from seabed (0-2 cm) sediments.

We report the presence of a prominent bathymetric expression of the Fitzroy River palaeochannel on the continental shelf of the southern Great Barrier Reef (GBR), Australia. The Fitzroy River, and the Burdekin River are the two largest point sources of terrigenous sediment to the GBR, which represents the worlds largest tropical mixed siliciclastic-carbonate sedimentary province. The Fitzroy River palaeochannel differs from that of the previously discovered Burdekin palaeochannel in that it has not yet been buried by sediments. Evidently, the dominance of platform reef rather than barrier reef geomorphology, coupled with macrotidal oceanographic conditions has limited aggradation behind the shelf edge, as postulated for the Burdekin region. Contrary to current models for the central GBR which suggest that slope sedimentation is limited to periods of transgression, the palaeo-Fitzroy probably contributed sediment directly to the continental slope of the southern GBR throughout the lowstand. Additionally, it appears that during the highstand, accumulation of terrigenous sediment on the middle and outer shelf has been minimal. The southern GBR represents a transition between the mainly terrigenous wave and ocean current dominated shelf of southeastern Australia, and the mixed siliciclastic-carbonate storm-influenced shelf of the GBR. The discovery of the Fitzroy River palaeochannel in the southern GBR physiographic setting provides new data by which the response of major rivers to sea level change can be characterised.

Geoscience Australia undertook a marine survey of the Leveque Shelf (survey number SOL5754/GA0340), a sub-basin of the Browse Basin, in May 2013. This survey provides seabed and shallow geological information to support an assessment of the CO2 storage potential of the Browse sedimentary basin. The basin, located on the Northwest Shelf, Western Australia, was previously identified by the Carbon Storage Taskforce (2009) as potentially suitable for CO2 storage. The survey was undertaken under the Australian Government's National CO2 Infrastructure Plan (NCIP) to help identify sites suitable for the long term storage of CO2 within reasonable distances of major sources of CO2 emissions. The principal aim of the Leveque Shelf marine survey was to look for evidence of any past or current gas or fluid seepage at the seabed, and to determine whether these features are related to structures (e.g. faults) in the Leveque Shelf area that may extend to the seabed. The survey also mapped seabed habitats and biota to provide information on communities and biophysical features that may be associated with seepage. This research, combined with deeper geological studies undertaken concurrently, addresses key questions on the potential for containment of CO2 in the basin's proposed CO2 storage unit, i.e. the basal sedimentary section (Late Jurassic and Early Cretaceous), and the regional integrity of the Jamieson Formation (the seal unit overlying the main reservoir). This dataset comprises total chlorin concentrations and chlorin indices from the upper 2cm of seabed sediments.

This resource contains surface sediment data for Outer Darwin Harbour collected by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Northern Territory Government (Department of Land Resource Management) during the period from 28 May and 23 June 2015 on the RV Solander (survey SOL6187/GA0351). This project was made possible through offset funds provided by INPEX-led Ichthys LNG Project to Northern Territory Government Department of Land Resource Management, and co-investment from Geoscience Australia and Australian Institute of Marine Science. The intent of this four year (2014-2018) program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps that underpin marine resource management decisions. The specific objectives of the survey were to: 1. Obtain high resolution geophysical (bathymetry) data for outer Darwin Harbour, including Shoal Bay; 2. Characterise substrates (acoustic backscatter properties, grainsize, sediment chemistry) for outer Darwin Harbour, including Shoal Bay; and 3. Collect tidal data for the survey area. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; physical samples of seabed sediments, underwater photography and video of grab sample locations and oceanographic information including tidal data and sound velocity profiles. These datasets comprise total sediment metabolism, mineral specific surface area and carbonate and element concetrations, and C and N isotopes of seabed sediments. A detailed account of the survey is provided in: Siwabessy, P.J.W., Smit, N., Atkinson, I., Dando, N., Harries, S., Howard, F.J.F., Li, J., Nicholas, W.A., Potter, A., Radke, L.C., Tran, M., Williams, D. and Whiteway, T., 2015. Outer Darwin Harbour Marine Survey 2015: GA0351/SOL6187 Post-survey report. Record 2016/008. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2016.008

In 2003, Geoscience Australia discovered three large patch reefs in the southern Gulf of Carpentaria (GA Survey 238; SS-03/2004; Harris et al., 2004). The submerged platform reefs (R1, R2 and R3) are located east of Mornington Island and appear to have been formed when sea level was ~30 m below its present position, however as the ship did not come prepared with a drill-core sampler, the sub-surface composition of the reefs was not determined. The submerged platforms support live hard corals in many locations and their discovery raised the question of the possibility of widespread reef occurrence in that region. Survey 276 was designed to deliver some answers to these questions. The current survey used rotary drilling of reefs R1, R2 and R3 which recovered coral material from 8 sites and confirmed the coral reef composition of these features. Multibeam sonar bathymetry and rotary drill cores were collected over two sections (R4 and R5) of a large (>100 km long) submerged platform that extends westwards from Mornington Island. The platform exhibits a Karst erosion surface, exhibiting drainage and depressions with raised rims, overprinting relict reef-growth geomorphic features. Reef growth features include raised rims, spur and groove reef front and elevated back-reef mounds. Other platform reefs were mapped in the south-western Gulf (R6 and R7) and in the Arafura Sea (R8). Rotary drilling has confirmed the coral reef composition of these features. Preliminary assessments of the recovered drill cores indicate that reef growth has persisted in the region for several glacial cycles, extending over at least the past 120,000 years. Dating of Holocene corals by the U/Th method demonstrates that a phase of rapid (1-2 m per kyr) reef growth occurred at most sites between 9 and 7 kyr before present, with zero or much reduced growth rates occurring after 7 kyr ago. Although coral growth occurs in many areas, the production of carbonate has not been sufficient to build the reef-tops upwards to the present sea level. The observations of live corals, but low carbonate production rates, are consistent with a 'catch-up' reef growth pattern, in which the upper surfaces of the reefs are submerged 20 to 30 m below present sea level, with isolated local reef-tops having reached to within 18 m of the sea surface. An analysis of the hypsometry of the reef surfaces indicates that platform surfaces at all sites (R1 to R8) are confined to two narrow depth intervals, centred at 26.8 ± 1 m and 30.7 ± 0.3 m. The good correspondence of hypsometric peaks indicates regionally significant phases of carbonate deposition during a prolonged, Pleistocene sea level still stand. This voyage has proved that the southern Gulf of Carpentaria contains a previously unknown major coral reef province in Australia. The reefs support locally diverse and luxuriant coral growth. From a management perspective, the slow rates of coral growth point to the need for protection of these reef systems because of their limited capacity to recover from natural or human-induced disturbances.

<p>This resource contains surface sediment data for Outer Darwin Harbour collected by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Northern Territory Government (Department of Land Resource Management) during the period from 28 May and 23 June 2015 on the RV Solander (survey SOL6187/GA0351). This project was made possible through offset funds provided by INPEX-led Ichthys LNG Project to Northern Territory Government Department of Land Resource Management, and co-investment from Geoscience Australia and Australian Institute of Marine Science. The intent of this four year (2014-2018) program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps that underpin marine resource management decisions. The specific objectives of the survey were to: <p>1. Obtain high resolution geophysical (bathymetry) data for outer Darwin Harbour, including Shoal Bay; <p>2. Characterise substrates (acoustic backscatter properties, grainsize, sediment chemistry) for outer Darwin Harbour, including Shoal Bay; and <p>3. Collect tidal data for the survey area. <p>Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; physical samples of seabed sediments, underwater photography and video of grab sample locations and oceanographic information including tidal data and sound velocity profiles. This dataset comprises O2 consumption and CO2 production rates measured from core incubation experiments conducted on seabed sediments. <p>A detailed account of the survey is provided in: <p>Siwabessy, P.J.W., Smit, N., Atkinson, I., Dando, N., Harries, S., Howard, F.J.F., Li, J., Nicholas, W.A., Potter, A., Radke, L.C., Tran, M., Williams, D. and Whiteway, T., 2015. Outer Darwin Harbour Marine Survey 2015: GA0351/SOL6187 Post-survey report. Record 2016/008. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2016.008

Three areas in the Torres Strait-Gulf of Papua region were selected for detailed study of sediments and benthic fossil biota. These areas form a transect across the shelf from the Fly River Delta to the shelf edge, near the northern extremity of the Great Barrier Reef. The Torres Strait-Gulf of Papua shelf is a shallow, low-gradient platform, where the shelf edge occurs between 120 and 140 m depth. In the study area, where the sediments range from muddy to gravelly carbonate sands, the sediment deposition rates are low and the relict content of sediment is often high. The three areas show distinct differences in benthic foraminiferal assemblages as indicated by relative abundances at the order level, as well as distribution patterns of individual species; these differences are also reflected in the total microbiotic communities. Given the high relict content in the surface material across these sites, a foraminiferal preservation scale was developed to assess the extent of reworking. Taphonomic features indicate that abrasion is the main factor affecting preservation. Despite poor preservation of the foraminiferal tests, the benthic foraminiferal species have a strong correlation to water depth, indicating that transportation pathways are short. Application of multivariate statistics to analyze the relationship between environmental attributes and the distributions of the microbiota and foraminiferal species indicates the additional importance of factors including percent carbonate mud, percent gravel, organic carbon flux, temperature, salinity and mean grain size. The benthic foraminifera produce a much stronger correlation to the environmental variables than the microbiota, indicating that these organisms can provide a detailed assessment of habitat types.

Description of evolution of shelf terraces developed on North West Shelf

Multibeam sonar mapping, underwater video and drill-cores have revealed the existence of widespread submerged coral reefs in the southern Gulf of Carpentaria, Australia. Seven reefs have been mapped to date using multibeam sonar and existing bathymetry data indicates as many as 50 other reefs may be present. The reefs are 14 to 30 m below present sea level and therefore invisible to optical remote sensing tools, which explains why they have only recently been identified. The time of colonisation and reef growth commenced in the early Holocene (11 to 10.5 kyr BP) and growth rates of 0.95 to 4 m kyr-1 were attained but reef growth had stopped in most locations by around 8.0 kyr BP, showing a classic "give-up" reef growth history. Reef growth in the late Holocene (2-3 kyr BP) was measured at only one of the reef sites. Our study reveals that the reefs in the southern Gulf of Carpentaria have some of the deepest Pleistocene foundations, the oldest framework coral and shortest-lived Holocene section known in Australia.