Geochemical survey in the 1:100000 sheet of Bazman
Geochemical exploration was done by stream sediment sampling method in the 1:100000 sheet of Bazman that is located in the Sistan and Baluchestan Province. This sheet is located in the 1:250000 quadrangle of Iranshahr between 60 to 60 30'E and 28 to 28 30'N. The sheet includes four 1:50000 sheets of east Bazman, east Sargah, Bazman and Sargah. From geological viewpoint the region is situated in the Southeast Iran structural zone at north of Jazmurian depression. The area is accessible through Bazman-Iranshahr and Bazman-Bam roads. The area that belongs to the Jebal-e Barez zone has a continental Precambrian basement with Paleozoic platform deposits. Lithology of the area includes granite, alkali granite, conglomerate, shale, sandstone, limestone, dolomite, andesite, andesi-basalt, pyroxene hornfels, and hornblende hornfels. Faults of the area are N-S and NW-SE tending.
The sampling network was designed on the base of weight center of drainage basins that were drawn using aerial photographs and topography maps. Geological and structural factors were also effective in the network design. Considering the total area of the sheet that was 2160 square kilometers, 662 sampling points were designed. All samples were analyzed for 20 elements including Pb, Ni, Mo, Sn, Ag, Co, Cu, B, Zn, Cr, Ti, Mn, Sr, Ba, Au, As, Sb, Be, Hg and W. Au was analyzed by spectrography method, W and Mo by polarography and other elements by atomic absorption.
After obtaining the analysis data, they were processed to identify available geochemical anomalies in the area. To check the identified anomalies, we used heavy mineral sampling method. Heavy mineral sampling was done from stream meanders, intersections, troughs and so on. At whole 143 heavy mineral samples were taken from this sheet.
From 14 geochemical anomalies in the area, three zones were introduced for further studies, after compilation of all data and field checking. These zones include:
- Garbord at east of Bazman: it is located between 60 09' 25" to 60 15' 56" E and 27 50' 43" to 27 57' 27" N. This zone that shows anomaly of Co, Zn, Be and Au consists of granite, granodiorite, sandstone, shale, thin-bedded limestone and andesite. Heavy minerals include pyrite oxide, scheelite, native copper, barite, corundum, and vanadite.
- The second anomaly in the Espizar is located between 60 05' 29" to 60 20' 36" and 27 41' 12" to 27 52' 06" at southwest of Bazman. This zone shows anomaly of Ag, As, W, Sb, Pb and Zn. Available heavy minerals in the samples include pyrite oxide, scheelite, gold, barite, chalcopyrite, and malachite.
- The anomaly number three in the Maki river is located at northeast of Bazman between 60 18' 57" to 60 26' 10" and 27 52' 06" to 28 N. the upstream rocks include intermediate volcanics, shale, tuff, and sandstone. 18 heavy mineral and 20 XRD samples from the area shows that the activity of Kaskian fault has caused the intensive alteration along the fault. This zone is anomalous for As, Sn, Au, Cu, Zn, Mo and Be.