Lineament extraction and enhancement
The analysis of lineaments in airborne geophysical data is one of the most important stages of the geological interpretation of these data. In addition to the obvious applications such as the annotation of dykes, faults, and basement lithological trends, the method can be applied directly to the detection of paleochannels and strand lines.
Lineament detection is thus of prime interest in the search for a number of commodities, including placer gold/tin deposits, heavy minerals and uranium.
LINEAMENT_Filter is a proprietary methodology developed by Minty Geophysics for the extraction and enhancement of linear features in gridded airborne geophysical data. The filter is loosely based on the radon transform as applied to the enhancement of image data. However, our implementation also has an automatic-gain-control element that attempts to scale all the lineaments to approximately the same amplitude. So the lineaments are not suitable for quantitative modelling as their amplitudes have been arbitrarily adjusted.
An example of the application of the method is shown below. The data is from the Fowler’s Gap survey, Corona, NSW, Broken Hill Exploration Initiative, 1995. The top image is a gradient-enhanced pseudocolour of the Total Magnetic Intensity. The bottom image shows the lineaments extracted using LINEAMENT_Filter. The data are courtesy of Geoscience Australia.