Pseudocolour image of the ratio between uranium and thorium 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 uranium relative to thorium and warmer colours represent the opposite. Variations in U/Th ratio are caused varied mineral compositions in host rocks and soils. This statewide image was generated by merging many individual airborne radiometric surveys.

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.

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.

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.

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.

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.

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.

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.

This vector file contains the location of reprocessed surveys and their acquisition parameters. These reprocessed surveys are from airborne geophysical surveys that have been submitted to the NSW government by exploration and mining companies. They have been publicly released under the NSW Mining Act 1992.