Regional lineament detection using bottom-up object-based image analysis methods

Abstract

The SW England region is a world-class tin orefield but the current state of regional lineament mapping is inconsistent. Whilst recent geological mapping in the region is of high quality, the coverage is incomplete and newly mapped districts are interspersed with the previous generation of geological mapping. The purpose of this contribution is to demonstrate how the regional structural geology can be mapped using semi-automated lineament detection techniques to produce a consistent lineament network from airborne geophysical data. The technique of bottom-up Object-Based Image Analysis (OBIA) has been developed to efficiently integrate multiple datasets to create a composite lineament network. Furthermore, the method requires minimal user input to guide the lineament detection. The method is tested over the SW England region of the UK which is covered by the Tellus South West project. High resolution airborne geophysical data including magnetic, radiometric and LiDAR datasets were colleceted as part of the survey work. The integrated approach results in a consistent regional lineament network that captures the known structural trends derived from field-based studies. The newly-derived data provide a new baseline dataset that can be used for future exploration for tin-tungsten, base metal and geothermal deposits.