Systematic geochemical exploration in the Hudian 1:100000 sheet
Geological Survey of Iran
The study area is located in the Iranshahr City of Sistan and Baluchestan Province, between 59 to 59 30' E and 27 30' to 28 N. It includes 1:50000 sheets of Hudian, Hamidabad, Chehelkenar and Ziarat.
Lithology of the area involves conglomerate, shale, sandstone, limestone, dolomite, andesite, andesibasalt, olivine basalt and tuff.
This area belongs to the Southeast Iran structural zone that includes Jazmurian subzone. The sampling network was designed on the base of topography maps and aerial photographs to have maximum compatibility with the weight center of drainage basins. Considering the 2160 square kilometers area of the sheet, 619 sampling points were planned. But because of accessibility and security problems, only 509 samples were taken.
Each samples involved 500 gr stream sediments of 80 mesh of which 100 gr were posted to laboratory for analysis the rest was archived. The samples were analyzed for 22 elements including Bi, Se, Pb, Ni, Mo, Sn, Ag, Co, Cu, B, Zn, Cr, Ti, Mn, Sr, Ba, Au, As, Sb, Be, Hg, W. Au was analyzed by atomic absorption and other elements by ICP-Mass method.
After obtaining the analysis data they were processed to determine the geochemical anomalies. Then the anomalies should be checked in the filed. We used heavy mineral sampling method for checking the anomalies. Sampling points were selected on the base of geology, structure, placers, rock exposures and topography. Sampling was done from course intersections, bend, trough, and so on. Samples were taken from depth and sieved by 20–mesh. At whole, 126 stream sediment samples were taken from the Hudian sheet.
12 geochemical anomalies were identified and controlled by heavy mineral sampling. Finally one zone introduced for more exploration.