SIC

Satellite imagery and aerial photography have proven to be important tools in support of mineral exploration projects. They can be used in a variety of ways. Firstly they provide geologists and field crews the location of tracks, roads, fences and inhabited areas. This is important for mapping out potential access corridors for exploration areas and considering the environmental impact of large project. The satellite map data is also useful for mapping outcrops and regolith systematics and vegetation cover across exploration blocks and over regional areas.

The Morenci satellite image below is an open-pit copper mine in southeast Arizona is North America’s leading producer of copper. This processed and interpreted ASTER image used short wavelength infrared bands to highlight in bright pink the altered rocks in the Morenci pit associated with copper mineralization.

Satellite images can also benefit geologists, scientists, and exploration managers due to the multiple bands that the satellites carry which allow them to interpret wavelengths that cannot be seen by the human eye. Near infrared, short wave infrared, and thermal infrared can be used to identify the difference in structural features of the earth’s surface.

Multispectral imaging and thematic mapping allows researchers to collect reflection data and absorption properties of soils, rock, and vegetation. This data could be utilized by trained photogeologists to interpret surface lithologies, identify clays, oxides, and soil types from satellite imagery.

In the example below, the second image displays short wavelength infrared bands 4, 6, and 8 as RGB. In this wavelength region, clay, carbonate, and sulfate minerals have diagnostic absorption features, resulting in distinct colors on the image. For example, limestones are yellow-green, and purple areas are kaolinite-rich. The third image displays thermal infrared bands 13, 12 and 10 as RGB. In this wavelength region, variations in quartz content appear as more or less red; carbonate rocks are green, and mafic volcanic rocks are purple.