فهرست مطالب mahyadin mohammadpour

In integrating geospatial datasets for mineral potential mapping (MPM), the uncertainty model of MPM can be inferred from the Dempster – Shafer rules of combination. In addition to generating the uncertainty model, evidential belief functions (EBFs) present the belief, plausibility, and disbelief of MPM, whereby four models can be simultaneously utilized to facilitate the interpretation of mineral favourability output. To investigate the functionality and applicability of the EBFs, we selected the Naysian porphyry copper district located on the Urmia – Dokhtar magmatic belt in the northeast of Isfahan city, central Iran. Multidisciplinary datasets- that are geochemical and geophysical data, ASTER satellite images, Quickbird, and ground survey- were designed in a geospatial database to run MPM. Implementing the Dempster law through the intersection (And) and union (OR) operators led to different MPM performances. To amplify the accuracy of the generated favourability maps, a combinatory EBFs technique was applied in three ways: (1) just OR operator, (2) just And operator, and (3) combination of And and OR operators. The plausibility map (as mineral favourability map) was compared to Cu productivity values derived from drilled boreholes, where the MPM accuracy of the hybrid method was higher than each operator. Of note, the success rate of the hybrid method validated by 21 boreholes was about 84%, and it demarcates high favourability zones occupying 0.67 km2 of the studied area.

The Jebal Barez area is situated in the Urmia-Dokhtar magmatic belt, and the porphyry copper mineralization in this region has close relationship with faults and granitoid masses. Determination of the structural lineaments is a good guide to identify the location of copper mineralization in the region. In this paper, an automatic algorithm was used to extract the lineaments from ASTER images. This algorithm can highly reduce user errors and runtime. In this paper, the CANNY algorithm was used as an edge-detector filter while Hough transform was used to extract linear features from satellite imagery. Finally, after investigating and detecting their operation, the faults associated with copper mineralization were recognized in the region. According the rose-diagram, two fault systems were highlighted that the main fault system is located along the NW-SE, and the fault system along the N-S boundary forms a small fraction of the total fractures in the region. the fault density map of the area shows a high potential for porphyry copper mineralization. In order to investigate the success of the ASTER images in extracting faults in the region these faults were compared with the faults of geology map, that 63.05% of them had overlapping with geology faults.