This is a preliminary low-resolution, pseudocolour image of airborne acquired Bouguer gravity with a histogram-equalised colour stretch. Cooler colours indicate lower Bouguer gravity values and warmer colours represent higher values. Bouguer gravity compensates for variations in latitude, 'free-air' elevation and Bouguer correction (assuming a crustal density of 2.67 T/m³). This image shows airborne gravity data from a survey that is ongoing. The Department of Customer Service has contracted two experienced specialist companies to fly the airborne survey. Final data will be available in 2024 at a higher resolution. Preliminary data should not be used in geological interpretations.

Map blocks and map units are based on a system originally devised by the British Ordinance Survey. Each 1:1 million scale map sheet is subdivided into 3456 graticular map blocks, each measuring 5’ of latitude by 5’ of longitude. These map blocks are further subdivided into 25 1’ by 1’ map units. A map unit is approximately 3 square kilometres in size.

The petrophysics database contains petrophysical (rock physical properties) data managed and acquired by the Geological Survey of NSW (GSNSW). Petrophysical properties recorded are: magnetic susceptibility (volume normalised); principal axes and degree of anisotropy of magnetic susceptibility; natural remanent magnetisation (NRM) intensity and direction; remanent magnetisation component directions; Koenigsberger (Q) ratio; saturated density; dry density; grain density; porosity. Vector and tensor magnetic properties (remanence and AMS) are oriented to in-situ (geographic) and fold-corrected (stratigraphic) coordinates where sample and bedding orientation are known.

Greyscale image of first vertical derivative (1VD) of isostatic residual gravity (Iso-grav). The 1VD filter shows the rate of change in the isostatic gravity data. Darker tones indicate lower values and lighter tones represent higher values. Attention: Please ensure your version of the NSW gravity merges contains the date ‘2024-10-30’ in their filename. An update was made to remedy location errors in the initial release. Apologies for any inconvenience.

In 1994 the Lightning Ridge Mining Board determined that the title ‘Preserved Fields’ would be applied to older mining areas which would not be returned to their previous land use, adopting less strict rehabilitation standards.

AEM curtains are a set of cross-sections generated using geophysical inversion to convert AEM data to conductivity (m/S) versus depth below surface (m). These data represent the conductivity of soil and rocks to a depth of about 400 m. A pseudocolour-stretch has been applied to the data. Blue represents low conductivity values and red represents high values. The colours vary due to; (1) natural variations in the electrical properties of soils, rocks, minerals and groundwater, (2) man-made structures, radio-transmissions and lightning strike and (3) AEM system artefacts.

The Geological Survey of NSW developed a Seamless Geology of UTM Zone 56 during 2014 as part of a project to develop a seamless vector geology dataset of the best available geological mapping data covering the whole of NSW.The overarching aims of the Statewide Seamless Geology Project were to: (i) compile the different original scales, formats and rock unit naming conventions into a consistent, statewide format; (ii) edge-match the geology across existing map sheets; and (iii) interpret the basement geology under cover. The resulting geodatabase comprises a series of layers which include: (i) solid basement geology; (ii) cover rocks (defined as undeformed and unmetamorphosed); (iii) Mesozoic igneous rocks; and (iv) Cenozoic sedimentary and igneous rocks. The project was divided into 3 major stages corresponding to the UTM zones which divide New South Wales. This dataset includes the seamless geology layers from the NSW portion of UTM Zone 56 (ie.east of 150 degrees longitude to the coast).

The petrophysics dataset contains petrophysical (rock physical properties) data acquired by the Geological Survey of NSW. It stores measurements of samples and mapping sites collected under the Field Observations database, including from drillholes. It currently covers the following techniques: mass properties, electrical, radiometric, seismic rock physics, magnetic susceptibility and magnetic remanence. It contains raw readings and calculated results, from field and laboratory environments. Vector and tensor magnetic properties (remanence and anisotropic magnetic susceptibility (AMS)) are oriented to in-situ (geographic) and fold-corrected (stratigraphic) co-ordinates where sample and bedding orientation are known.

This vector contains the boundary and flight lines of Infill Area D. Infill Area D is part of the MinEx Collaborative Research Centre (CRC) Cobar Airborne Electromagnetic (AEM) survey. This survey was a collaboration between the Geological Survey of NSW (GSNSW) and Geoscience Australia. Infill D was funded by Legacy Minerals Pty. Ltd. Regional lines were funded by GSNSW.

In 2016, the Geological Survey of NSW (GSNSW) published a state-wide depth to basement 3D model (Robinson 2016, 2017). Since then, new geological and geophysical data have been released and used for the construction of basin-scale 3D geological models for the southern Thomson Orogen and the Sydney, Gunnedah and Bowen basins (Davidson 2019; Oliveira and Davidson 2019; Oliveira et al. 2019). The basement topography under these regions was refined and the results have now been incorporated into the updated state-wide depth to basement 3D model reported herein.