Mineral Exploration and the Digital Terrain Revolution

摘要

Over the past two decades technological advances have revolutionized the imaging of Earth's surface. Traditional aerial photographic interpretation has given way to high-resolution, 3-dimensional, digital elevation data as well as detailed color rendering and hyperspectral imaging. The relevance of these technologies to mineral exploration is very much a work-in-progress with significant advancements yet to be made. Obviously these technologies are best applicable in frontier areas where surface manifestations of mineralization are visible or not yet fully characterized. Hyperspectral imaging from airborne and ground-based platforms is now firmly established as a viable tool for the explorationist in desert terrains or surfaces with minimal vegetation cover. LiDAR is an acronym for 'light detection and ranging' and is a powerful tool for identifying outcrops and bedrock patterns in highly-vegetated terrains. While widely employed in fields such as public infrastructure and forestry, LiDAR has received relatively less attention in the area of mineral exploration. Airborne LiDAR now has demonstrated capabilities for characterizing lineaments, such as mineralized faults in steep and vegetated terrains that constitute some of the important frontier areas for mineral exploration. Ground-based LiDAR in conjunction with hyperspectral imaging of outcrops is at the cutting edge of reservoir characterization in petroleum research, but to date it has not been extensively used in mineral exploration. Three-dimensional imaging of outcrops using off-the-shelf digital cameras and associated software is easily available to the general public and should be in the toolkit of all professional field geologists. This paper presents examples of how all these relatively new technologies can help the explorationist and points out some of the advancements that can be expected in the next few years. Specific field areas in Nevada and the rest of the western U.S. are highlighted, and sources of publically available resources are reviewed herein.