This layer shows the boundaries of each airborne gravity survey acquired by the NSW Government. Details on the spacing and age of the gravity data within each project area are in the attributes. The information contained in this publication is based on knowledge and understanding at time of writing (April 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.

The NSW Government has acquired hyperspectral data to aid geological interpretation. The location of hyperspectral coverage is contained within this layer. The information contained in this publication is based on knowledge and understanding at time of writing (April 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.

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.

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.

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.

Isostatic residual Bouguer gravity image overlain on tilt-filtered total magnetic intensity reduced to the pole (Tilt TMI RTP) image. The image is a partially-transparent pseudocolour layer of Isostatic residual Bouguer gravity, with a histogram-equalised colour-stretch, overlain on a greyscale intensity layer of the Tilt TMI RTP, with a histogram-equalised stretch. Bouguer gravity compensates for variations in latitude, 'free-air' elevation and Bouguer correction (assuming a crustal density of 2.67 T/m³). The isostatic correction removes the effect of variations in the thickness of the Earth’s crust due to changes in topography. The tilt-angle filter of total magnetic intensity produces a local positive maximum over a magnetic source and is zero near the edge of the source, and is useful for tracing geological structure below variable depths of cover.

Pseudocolour image of the percentage of potassium (K%) in the upper 20 centimetres of the ground. Cooler colours indicate lower abundances of potassium and warmer colours represent higher abundances. Variations in potassium values are caused by varied mineral compositions in host rocks and soils. This statewide image was generated by merging many individual airborne radiometric surveys.

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.

This vector contains the flight lines from the MinEx Collaborative Research Centre (CRC) Cobar Airborne Electromagnetic (AEM) survey. This survey was a collaboration between the Geological Survey of NSW and Geoscience Australia

Geothermal gradient model (2023) created by Geognostics with support from government and industry. The geothermal gradient describes how temperature increases with depth inside the Earth. It is expressed in degrees Celsius per kilometre (°C/km). The linear geothermal gradients are from the top of SEEBASE to the surface. These were calculated using the combined heat-flow contribution of multiple crustal heat sources including upper mantle, radiogenic upper crust, and sediment thickness. The highest calculated geothermal gradients are generally related to areas interpreted to be underlain by granitic intrusions in the basement. The composition and heat production characteristics of the granites are largely unconstrained by analyses