Application of the Crosta technique for porphyry copper alteration mapping, using ETM+ data in the southern part of the Iranian volcanic sedimentary belt

Many of the known porphyry copper deposits in Iran are situated in the Central Iranian volcanic Belt. The area under study is located in the southern part of this belt and covers an area of about 6600 km(2). The climate in the area is semi-arid. Given the poor soil development and poor vegetation cover but abundant outcrops, the arid/semi-arid part of the belt is most suitable for remote sensing study. Enhanced Thematic Mapper plus (ETM+) images have been used for alteration mapping. Crosta method was found useful for enhancing the areas in which the regolith contains a high proportion of hydroxyl and iron oxide minerals. The Crosta method has been used on selected 4 and 6 bands. Areas with iron oxide and hydroxyl minerals have been enhanced by using six bands of ETM+ data. (C) 2003 Elsevier Ltd. All rights reserved.