Inversion of geophysical data and potential mapping of Robat-Arregijeh Pb-Zn deposit, Khomein, Markazi province, using integration of exploratory information in GIS

In Robat-Arregijeh Pb-Zn deposit, various exploration activities have been carried out through two methods, indirect and direct in two stages. In current research, at first, depending on the exploration data in first stage including geophysical data surveyed by gradient configuration, surface explorations and geology information, promising areas were detected using knowledge driven fuzzy logic method. To achieve this goal, various layers of evidence including geophysical, faults, geochemical and geological layers were prepared in ArcGIS environment. Afterward for weighting and prioritization of exploration layers, among the variety of multi-criteria analysis and decision making (MADM) methods, fuzzy TOPSIS method was selected due to high sensitivity and accuracy in decision making. In order to perform hierarchical chart, Delphi method was also employed. In this regard, four criteria comprising accuracy and reliability of the results, time and cost of operation, number of data and interpretation of the results were considered. After ranking the informational layers and according to them prioritize, final mineral potentials map was produced using weighted sum method. Then, deep geophysical exploration in the region was validated through determination of linear correlation between geophysical data after smooth inverse modeling with lead-zinc assay of deep exploratory boreholes (related to the second stage of exploration operation) located on the geophysical profiles. Finally after ranking the informational layers, the mineral potential map was validated with accuracy percentage of about 56% through the existent borehole assay data.