LITHOLOGIC MAPPING USING LANDSAT THEMATIC MAPPER DATA.

The paper is in abstract form. It discusses the Landsat-4 Thematic Mapper (TM), with its new near infrared bands centered at 1. 65 mu m and 2. 20 mu m and spatial resolution of 30 m, which has been used to distinguish rocks containing minerals having ferric-iron absorption bands in the visible and near-infrared and Al-O and CO//3 absorption bands in the 2. 1-2. 4 mu m regions. On the basis of characteristic absorption bands, digitally processed TM data were used to differentiate vegetated from non-vegetated areas, limonitic from nonlimonitic rocks, rocks containing minerals having absorption bands in the near-infrared region from rocks lacking the infrared absorption bands. Specific minerals were detected in both the humid eastern and semi-arid western United States. The absorption bands in the near-infrared region were used to detect kaolinite in open-pit exposures of a kaolin mining district near Macon, Georgia; calcium carbonate in the beach sands along the east coast of Florida; and kaolinite, alunite, jarosite, sericite and gypsum in natural exposures near Boulder City, Nevada.