Mineral potential map by a knowledge driven GIS modelling: An example from Singhbhum copper belt, Jharkhand Geology and mineralisation: An overview The Singhbhum Shear Zone is located along the southern fringe of the Proterozoic fold belt of North Singhbhum which is sandwiched between the early Archean cratonic nucleous represented by Singhbhum and Bonai granite, to the south and Proterozoic Chottanagpur Granite Complex to the north. The intervening gap area between Singhbhum and Chotanagpur crustal provinces is occupied by a curvilinear belt of metasedimentaries belonging to Dhanjori and Singhbhum Group of Proterozoic age. The Singhbhum shear zone which has developed in this Proterozoic belt, is a northerly dipping arcuate ductile shear zone ( Ghosh & Sengupta, 1987) marked by lenticular mylonite zone. The trend of the shear zone changes from E-W in the western part to NNE-SSW in the eastern part. The rocks within the Singhbhum Shear Zone form a tectonic mélange comprising granite mylonite, quartz-mica phyllonite, quartz tourmaline rock and deformed volcanic and volcano clastic rocks (Mukhopadhyay & Deb, 1995). The shear sense indicator suggests a thrust type of deformation (Mukhopadhyay & Deb, 1995). The zone is characterised by mylonitisation, syntectonic with the first phase of deformation. The mineralised zone –Singhbhum Copper Belt runs close to the interface of Singhbhum Group of rocks mainly schists and Dhanjori volcano-sedimentary package. The copper mineralisation in this belt consists of number of parallel to sub-parallel discontinuous lodes aligned along the major tectonic grains of the area. The predominant sulphide minerals are chalcopyrite, pyrite and pyrrhotite. The mode of the occurrence varies from massive to braided veins, stringers, dissemination, discordant to sheet like bodies and also as en-echelon veins.Existence of structural and lithological controls for the mineralisation have been suggested by several workers. Sarkar et.al.(1986), suggested that sulphide mineralisation in this belt is confined mainly within certain stratigraphic horizon adjacent to the Dhanjori metavolcanics. The remobilization has mainly taken place along shear bands. The general trend of the ore body is controlled by the local trend of the slip planes (report on Project Singhbhum, 1991) . The wall rock alteration in the form of chloritisation, sericitisation, biotitisation, tourmalinisation and albitisation are common. Exploration model for copper in Singhbhum copper belt: Any attempt of deposit modelling for Singhbhum Copper Belt takes into consideration certain general observations made by earlier workers, regarding characteristics of copper mineralisation in relation to lithology, tectonics, mode of emplacement etc. They can be summarised as follows:
Geological Survey of India has carried out stupendous work in the area (Fig 1) under discussion for last several years by way of mapping on scale 1: 63,360 and extensive Airborne Geophysical Surveys. Electromagnetic, magnetic and scintillometric sensor surveys have also been carried out, followed by ground geochemical and geophysical surveys in selected areas to assess their mineral potential. Nearly 600 boreholes were drilled in the area to study the nature of the ore bodies and estimation of reserve, after detailed geological mapping of prostective locations (on 1:10,000; 1:5,000; 1:2000 scale).  The present paper deals with the result of the analyses of the collated digital data and maps from published and unpublished reports of GSI. Apart from the digital information, the attribute data available in various thematic domains was also consulted. Extensive help was also sought from the synthesis work done under project Singhbhum. The GIS dataset comprise of following layers: Lithological evidences
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