Preliminary exploration of metallic elements in the northeast of Iranshahr
This report presents the result of preliminary exploration of metallic deposits in the Iranshahr region that is 500 Km2 wide. The project was done based on the 1:50000 topography maps of Dustabad, Daman, and 1:250000 geology and topography maps of Iranshahr. The area has dried climate and the local peoples are occupied in agriculture and livestock.
The basement of the area is oceanic type and the region was evolved through Upper Cretaceous to Holocene by regression of marine basin. Dominant rocks are flysch, ophiolitic rocks, pillow basalts, and metamorphosed sediments. Tectonic faults are NW-trending.
342 stream sediment samples and 101 heavy mineral samples were taken and analyzed for geochemical survey on the scale 1:20000. The samples were analyzed at ALS-Chemex laboratory of Canada for 35 elements. Censored values such as Au, Hg and Sb were replaced by the Kohen likelihood function. Then data were analyzed by Excel and Spss softwares. The data were normalized and then analyzed by multi-variable methods. Correlation of Au, Cu, Hg, Cr, Co, Ni, Fe and Mg were calculated. Au is an independent variable in the region. Ni, Cr, Co, Fe and Mg show high correlation. Correlation of Hg and As is also high. Factorial anomalies were mapped and described in the third chapter. The fourth chapter includes the result of heavy mineral study. Cinnabar is a considerable mineral in the southern portion of the region. In some samples there were more than 10 particles of cinnabar mineral. In the control phase, seven filed survey conducted through which 137 samples were taken for various analyses such as geochemistry, petrography, polished section, crushing, and mineralogy.
The next chapter focuses on the error estimation procedure that was done using 18 repetitive samples. The values of Ag, Cd, Te, U, W, Ga, La and Bi in both analyses were below the sensitivity limit of instrument. Also the grades of Mo, S, Sb, As, B, Au, Na, Pb, Sc, Be, Ti and Hg is near the sensitivity limit of instrument. The result of repetitive analysis for other elements is reasonable.