The assessment of spatial correlation between location of deposits and faults using geostatistical methods: case study, Yazd province

Determining the promising area for ore deposits is one of the most important steps of prospecting in regional scales. There are many different methods for identifying these areas including geochemical and geophysical methods، remote sensing and sophisticated statistical methods. Based on the theory of spatial relations between the dispersion pattern of ore deposits and metallogenic provinces، mineralization belts، faults and structural factors، some new interpretative methods can be proposed in the preliminary exploration phase of the potential areas. In this study، the geostatistical methods were used، where the spatial location of faults and known metallic deposits were considered as the primary source of data to obtain their correlation (case study of metallic deposits in Yazd province). The research was performed on 807 major and minor faults and 76 metallic deposits، mainly from hydrothermal origins. The data was arranged in ArcViewGIS software environment. The geostatistical analysis was performed by defining the regionalized variable (distance between faults and deposits) in a Mathematica subroutine. Variography operations، in order to find the spatial structure، were performed on regionalized variable using Surpac software. It was also shown that the theory of spatial correlation was valid for the defined variable. In this work، the variography operation was used to find the direction and the range of the effect of faults and deposits. Variograms indicated that the possibility of ore deposits existence in an area could depend on the direction of the faults. By drawing the directional variogram and variogram map، the best stretches for more exploratory studies is shown to be parallel along the Azimuth 130◦ and 64 km distance. By revealing the spatial structure in different directions، the area of mineralization related to the faults and the number of ore deposits associated with major faults have been marked.