Geological mapping using Landsat Thematic Mapper imagery in Almeria Province, south-east Spain

Abstract Abstract. This paper describes the use of Landsat Thematic Mapper (TM) imagery for geological mapping in a tectonically-complex area of south-east Spain. The terrain includes the metamorphic basement rocks of the Betic Cordillera and the sedimentary strata of an intermontane basin. TM bands 1, 3 and 5 were used to produce a colour composite. Experimentation showed that this was the most effective band combination to discriminate rock types in the semi-arid study region. A combination of spectral and textural characteristics was used to identify and map rock types in the Nevado-Filabride and Alpujarride basement complexes, sedimentary strata in the Neogene Tabernas-Sorbas Basin and Quaternary drift deposits. Structural features were best shown by digital convolution using a directional filter. The enhanced images revealed a previously unreported fault and fracture belt on the northern side of the Tabernas Basin. The geological interpretation of enhanced TM imagery was locally checked in the field.