Springvale 1:250 000 interpreted geology

Brief description

This dataset is an interpretation of geology of the Springvale 1:250000 Sheet area based on airborne geophysics and gravity data, Proterozoic geology plus magnetic units in overlying cover rocks.

Lineage

Maintenance and Update Frequency: notPlanned

Statement: This map presents an interpretation of the geology of the Boulia 1:250 000 sheet area, based on airborne geophysical and gravity data. The interpretation was produced with reference to the mapped outcrop geology from D.H.Blake, 1987 - "Geology of the Mount Isa Inlier and Environs" Bureau of Mineral Resources, Canberra ACT 1:500 000 Scale Map. This map should be inspected to gain an understanding of the geological framework used for the geophysical interpretation. The airborne geophysical data were acquired in 1997 during a survey that was part of the National Geoscience Mapping Accord. The survey was flown by AGSO along east-west lines, 400 metres apart at a nominal terrain clearance of 80 metres. After the data were processed, the following images were generated: Total magnetic intensity (TMI), reduced to the pole (RTP), colour Analytic Signal of TMI TMI (RTP), with easterly illumination, colour First vertical derivative of TMI (RTP), greyscale First vertical derivative of TMI (RTP), with easterly illumination, colour Fractional vertical derivative (1.5) of TMI (RTP), greyscale Automatic gain control of first vertical derivative of TMI (RTP), greyscale TMI (RTP) upward continued 1000 metres, colour Potassium (red), Thorium (green), Uranium (blue) RGB colour composite Digital Elevation Model, with easterly illumination, colour Bouguer gravity, colour These images were combined with existing digital geology, topographical and borehole information in a GIS. The interpretation of the data consisted of two phases: Phase 1: Outlining magnetic sources. Phase 2: Correlating known geology with geophysical responses and outlining and identification of geological units. The images used for the interpretation and this geophysical interpretation map are available in digital format, suitable for use in most GIS applications.