This service represents a combination of two data products, the DEM_SRTM_1Second dataset and the Australian_Bathymetry_Topography dataset. This service was created to support the CO2SAP (Co2 Storage application) Project to create a transect elevation graph within the application. This data is not available as a dataset for download as a Geoscience Australia product. The DEM_SRTM_1Second service represents the National Digital Elevation Model (DEM) 1 Second product derived from the National DEM SRTM 1 Second. The DEM represents ground surface topography, with vegetation features removed using an automatic process supported by several vegetation maps. eCat record 72759. The Australian_Bathymetry_Topography service describes the bathymetry dataset of the Australian Exclusive Economic Zone and beyond. Bathymetry data was compiled by Geoscience Australia from multibeam and single beam data (derived from multiple sources), Australian Hydrographic Service (AHS) Laser Airborne Depth Sounding (LADS) data, Royal Australian Navy (RAN) fairsheets, the General Bathymetric Chart of the Oceans (GEBCO) bathymetric model, the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO satellite derived bathymetry (Amante and Eakins, 2008). Topographic data (onshore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd New Zealand topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008). eCat record 67703. IMPORTANT INFORMATION For data within this service that lays out of the Australian boundary the following needs to be considered. This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service. Geoscience Australia produces the 0.0025dd bathymetric grid of Australia specifically to provide regional and local broad scale context for scientific and industry projects, and public education. The 0.0025dd grid size is, in many regions of this grid, far in excess of the optimal grid size for some of the input data used. On parts of the continental shelf it may be possible to produce grids at higher resolution, especially where LADS or multibeam surveys exist. However these surveys typically only cover small areas and hence do not warrant the production of a regional scale grid at less than 0.0025dd. There are a number of bathymetric datasets that have not been included in this grid for various reasons.

This report provides a description of the activities completed during the Bynoe Harbour Marine Survey, from 3 May and 17 May 2016 on the RV Solander (Survey GA4452/SOL6432). This survey was a collaboration between Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and Department of Land Resource Management (Northern Territory Government) and the second of four surveys in the Darwin Harbour Seabed Habitat Mapping Program. This 4 year program (2014-2018) aims to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline information and developing thematic habitat maps that will underpin future marine resource management decisions. The program was made possible through funds provided by the 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 specific objectives of the Bynoe Harbour Marine Survey GA4452/SOL6432 were to: 1. Obtain high resolution geophysical (bathymetry) data for the deeper areas of Bynoe Harbour (<5 m), including Port Patterson; and, 2. Characterise substrates (acoustic backscatter properties, sub-bottom profiles, grainsize, sediment chemistry) the deeper areas of Bynoe Harbour (<5 m), including Port Patterson. Data acquired during the survey included: 698 km2 multibeam sonar bathymetry, water column and backscatter; 102 Smith-McIntyre grabs, 104 underwater camera drops, 29 sub-bottom profile lines and 34 sound velocity profiles.

As part of a multidisciplinary study of the region by Geoscience Australia and the geological surveys of New South Wales and Queensland, the mineral systems at the Cuttaburra and F1 prospects have been investigated with the aim of better understanding the prospectivity of the southern Thomson Orogen. Samples from three drill holes at the Cuttaburra prospect and three drill holes at the F1 prospect were studied in detail petrographically and analysed for the following: whole-rock geochemistry; S isotopes; Pb isotopes; molybdenite Re-Os geochronology; cassiterite U-Pb geochronology; and white mica 40Ar/39Ar geochronology. The results have been integrated with existing zircon U-Pb geochronology and company data to better characterise the geology, mineralisation, alteration, timing and geochemistry of the mineral systems. A new two-stage model of mineral system formation has been developed in which early Mo-W and later Au-base metal mineralisation both formed at ~425-430 Ma, probably coevally with granitoids that intruded Cambrian or younger metasedimentary rocks.

A benthic sediment sampling survey (GA0356) to the nearshore areas of outer Darwin Harbour was undertaken in the period from 03 July to 14 September 2016. Partners involved in the survey included Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Department of Environment and Natural Resources within the Northern Territory Government (NT DENR) (formerly the Department of Land and Resource Management (DLRM)). This survey forms part of a four year (2014-2018) science program aimed at improving knowledge about the marine environments in the regions around Darwin and Bynoe Harbours through the collection and collation of baseline data that will enable the creation of thematic habitat maps to underpin marine resource management decisions. This project is being led by the Northern Territory Government and is supported by the INPEX-led Ichthys LNG Project, in collaboration with - and co-investment from GA and AIMS. The program builds upon an NT Government project (2011-2011) which saw the collection of baseline data (multibeam echosounder data, sediment samples and video transects) from inner Darwin Harbour (Siwabessy et al. 2015). Here we present an account of the field methods and data summaries (location maps and comprehensive metadata) for the collection of 200 seabed sediment samples designated for grain size and inorganic elemental analyses, and organic matter concentration, source and reactivity measures. Metadata is also provided for seagrass observations and hardground occurrences. The seagrass observation data will be incorporated into DENR's seagrass database. The baseline environmental datasets acquired during this survey will be merged with like datasets from three other surveys conducted as part of the overall project to create a set of interpolated maps of abiotic parameters with full coverage for the region. Some of the maps will be integrated into final habitat mapping products. Baseline data from the survey will also be made publically available via the Geoscience Australia website (http://www.ga.gov.au/).

The geology and mineral prospectivity of the southern Thomson Orogen is poorly understood because the vast majority of its extent is buried beneath younger regolith and/or sedimentary rocks. To address this issue a collaborative program to drill 16 stratigraphic boreholes was proposed to collect samples of the basement geology that can be comprehensively analysed to improve the understanding of the geological evolution of this region. To reduce the uncertainty associated with intersecting the target stratigraphy at each of the borehole sites, estimates of the cover thickness were obtained by applying the geophysical techniques of refraction seismic, audio-magnetotellurics (AMT) and targeted magnetic inversion modelling (TMIM) prior to drilling. Refraction seismic was acquired at all 16 proposed borehole sites using a system with 48 single-component geophones and a propelled weight drop primary-wave source. At 14 of the sites clear basement refractors were observed in the data. At the two other sites, Nantilla 1 and Barrygowan 1, loss of signal due to seismic attenuation at far offsets meant that a clear basement refractor was not observed. With the exception of these two sites, three distinct refractors are generally observed in the data. Those with velocities ranging from 0.4 km/s to 1.5 km/s are interpreted as regolith, those ranging from 1.8 km/s to 2.4 km/s are interpreted as Eromanga Basin sediments, and those ranging from 3.9 km/s to 5.7 km/s are interpreted as metamorphic/igneous basement. Two-dimensional velocity models of the subsurface geology were then generated using the time-term inversion method, which allowed for the thickness of each layer to be estimated. Cover thickness estimates using refraction data vary widely from site to site, with the shallowest estimate being Overshot 1 (49 m - 55 m) and the deepest Adventure Way 1 (295 m - 317 m). These variations in cover thickness estimates from site to site are indicative of basement topography variations and are not error margins. Audio-magnetotelluric data was collected at ten sites by simultaneously deploying four porous pot electrodes, to collect the two orthogonal components of telluric data (Ex and Ey), and three magnetic induction coils, to collect the three components of magnetic data (Hx, Hy and Hz). For each dataset, a one-dimensional inversion model was produced, from which resistivity contrasts were identified and used to describe electrical conductivity discontinuities in the subsurface geology. In general, the models show a near-surface conductive layer with resistivity values ≤10 Ω·m overlying layers with continuously increasing resistivities with depth (up to 102-103 Ω·m). Those layers which were >10 Ω·m were interpreted as metamorphic/igneous basement rocks and were observed to occur at depths of ~100 m to ~300 m across the survey sites, except at Overshot 1 (38 m ±10%) and Barrygowan 1 (480 m ±10%). Targeted magnetic inversion modelling (TMIM) was applied to freely available, good quality, regional airborne magnetic survey data. Depth to magnetic source estimates were generated for 53 targets, with confidence ratings, using a dipping tabular source body to model targeted magnetic anomalies in the vicinity of the borehole sites. A combined depth estimate was generated using a distance and confidence weighted average from multiple depth estimates at all but two borehole sites. Only a single depth estimate was available at Adventure Way 1 while no depth estimates were generated at Eulo 1. These combined depth estimates provide cover thickness estimates at the sites as they are likely sourced from, or near, the top of basement. Of the ten proposed borehole sites with coincident AMT and refraction seismic data, five sites have overlapping cover thickness estimates. Cover thickness estimates from the TMIM overlap both the AMT and refraction data at four sites and at two sites where only the refraction depth estimates were available. 2 Estimating Cover Thickness in the Southern Thomson Orogen The cover thickness estimates presented in this report lower the risks associated with the proposed southern Thomson Orogen stratigraphic drilling program by reducing the uncertainty in intersecting the target stratigraphy at each of the borehole sites as well as allowing for better project and program planning. Successful completion of the stratigraphic drilling program in the southern Thomson Orogen will allow for each of these geophysical methods for estimating cover thickness to be benchmarked using actual cover thicknesses measured in the boreholes.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

Three geologists left Australia in 1951 to conduct geological surveys in Pakistan, under the auspices of the Colombo Plan which provides technical assistance for member countries in South and South East Asia. The main objects were to conduct an economic and general geological survey of a selected part of the Gilgit Agency, to examine the alluvial-gold prospects of the Chitral River, and, if time permitted, to discuss the Sind and East Bengal lignites with the Director of the Pakistan Geological Survey. The field notebooks contain the geological observations recorded by the geologists during their trip. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

Three geologists left Australia in 1951 to conduct geological surveys in Pakistan, under the auspices of the Colombo Plan which provides technical assistance for member countries in South and South East Asia. The main objects were to conduct an economic and general geological survey of a selected part of the Gilgit Agency, to examine the alluvial-gold prospects of the Chitral River, and, if time permitted, to discuss the Sind and East Bengal lignites with the Director of the Pakistan Geological Survey. The field notebooks contain the geological observations recorded by the geologists during their trip. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.