AEM data has been acquired by the NSW government through NSW Exploration, Discovery 2000 and New Frontiers Initiative funding. Contained within this vector file is the location of AEMsurveys and acquisition parameters. The information contained in this publication is based on knowledge and understanding at time of writing (February 2017). Because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date. The information contained in this publication may not be or may no longer be aligned with government policy nor does the publication indicate or imply government policy.

Please view Matthews and Sheldon (2024) for full description and instructions: Contact Sam at samuel.matthews@regional.nsw.gov.au if you have any difficulty accessing the paper.

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 modelled using constraints from drillholes, seismic, Seamless Geology, magnetics and gravity data. The results have now been incorporated into the updated Statewide 3D Basement Elevation Model reported herein.

Depth contours derived from the NSW Basement Elevation Model.

The semi-transparent Bouguer gravity image is displayed using cooler colours (blue) to indicate lower gravity values and warmer colours (red) represent higher values. The underlying greyscale tilt-angle filtered total magnetic intensity image has been reduced to the pole (Tilt TMI RTP). The tilt-angle filter of the total magnetic intensity produces a local positive maximum (white) over a magnetic source and is zero near the edge of the source (grey), and is useful for tracing geological structure below variable depths of cover. Both image layers were generated using a histogram-equalised colour-stretch. 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.

Greyscale image of first vertical derivative (1VD) of Bouguer gravity. Darker tones indicate lower values and lighter tones 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). 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.

Pseudocolour image of the ratio between uranium and thorium within the upper 20 centimetres of the ground. Cooler colours indicate lower abundances of uranium relative to thorium and warmer colours represent the opposite. Variations in U2/Th ratio are caused varied mineral compositions in host rocks and soils. This statewide image was generated by merging many individual airborne radiometric surveys.

Ground surveyed gravity data has been reported to the NSW government and released under the requirements of the NSW Mining Act 1992. Contained within this vector file is the location of surveys and acquisition parameters.

This layer shows a depth slice from a 3D resistivity model of the crust derived from an inversion of the AusLAMP NSW long period MT data.

Pseudocolour image of the ratio between thorium and potassium within the upper 20 centimetres of the ground. This image was generated using normalised input grids to avoid ‘divide by zero’ errors. Cooler colours indicate lower abundances of thorium relative to potassium and warmer colours represent the opposite. Variations in Th/K ratio are caused varied mineral compositions in host rocks and soils. This statewide image was generated by merging many individual airborne radiometric surveys.