Predictive GIS model for copper-gold porphyry deposits, Birjand volcanic-plutonic belt, east of Iran

Bidand volcanic-plutonic belt is located in east of Iran with the average area of 3000 km(2) and has a complex history of sedimentation, volcanic and intrusive igneous activity, and structural deformation from Mesozoic through Cenozoic. Maps showing spatial variation of Cu-Au porphyry potential in the Birjand belt have been generated by combining digital data from a variety of sources. The geologic processes that resulted in the formation of Cu-Au porphyry deposits can be recognized at the regional scale from diagnostic recognition criteria: 1) distribution and age, 2) structure, 3) alteration, 4) associated intrusive rocks, 5) host rocks, 6) geochemical feature, and 7) tectonic setting. The quantitative relationships between geologic, geochemical, and remote sensing data sets representative of the deposit recognition criteria and known copper and gold occurrences are determined using Index Overlay with multi-class maps analysis. The resulting weights for essential digital data from diagnostic recognition criteria are combined to predict mineral potential. The new porphyry discovery at the area made during June 2004 is in a favorable zone as predicted by this model.