
Semi-detailed Geochemical Exploration (1:20000) in Hired anomaly, 1:100000 sheet of Basiran
2002
Abstract
This area is located 4 Km far from east of Basiran village between 59.10 to 59.15 eastern longitudes and 31.55 and 32 northern latitudes. The study area is one of the 25 anomalies introduced by geochemical exploration in five sheets (1:100000) of south of Khorasan, selected after field studies.
As a result of geochemical exploration in Basiran sheet, an 80 Km2 wide anomalous area at south of Basiran village was selected for more detailed geochemical exploration. In this project 292 geochemical, 85 heavy mineral and 13 mineralized samples were analyzed. After analysis, the data were subjected to statistical analysis such as calculation of enrichment index and its normalization, multi-variable and cluster analysis. Dominant rocks in the area involve pyroxene-andesite, granite, granodiorite and tuff. Major faults strike NE-SW to E-W. Mineralization is in relation to E-W main faults and granitic and granodioritic plutonism, at contact of tuff and granodiorite. Mineralization of pyrite, chalcopyrite malachite and azurite has occurred along the E-W striking main faults and N-S minor faults. The ore grade is higher in minor faults. According to heavy minerals (cinnabar, pyrite, pyrite oxide, chalcopyrite and orpiment), gold mineralization is indicative.
The zone-I is highly anomalous from which 7 gold heavy mineral samples were identified plus to a cinnabar sample and much pyrite. Heavy minerals of the zone-II include 4 gold, 3 scheelite and 1 cinnabar and chalcopyrite sample. A gold sample, two scheelites and a cinnabar included in heavy minerals samples of zone-III.
Based on the results of mineralized samples, mineralized veins in andesitic tuff that contain pyrite, chalcopyrite, malachite and azurite, have for 1.16 ppm Au. Existing slag of the same vein contain 3.48 ppm Au.
A sample of a mineralized vein that contains malachite, hematite and jasper, had 7% Cu. The results show the correlation of these sets of elements.
1) Au, Ag, Sn, As, and W
2) Bi, Mo, Hg, Zn, Cd, Sb and Cu
3) Cr, Co and Ni
At whole the anomalous zone-I at southeastern flank of Siahkamar Mountain is more favorable. The report includes 20 maps.