Prospecting and Economical Evaluation of Heavy Minerals in Karkheh River Sediments, Khuzestan Province, Iran

摘要

The present study is on alluvial sediments with variable origin of Karkheh River, in order to recognize their heavy minerals' dominant pattern distribution. The aim of this study is to recognize economically heavy minerals' grade percentage and genetic models. 100 samples, collected from recent and old trace river sediments, have been considered for studies on 30 heavy minerals, which are separated by heavy liquid methods. Although the volume of heavy minerals in this area is negligible but the variation and local concentration of minerals is high and considerable. The heavy fraction was analyzed using XRD method to recognize heavy minerals and confirm microscopic mineralogy observations. The result analyzed by monovariance and covariance statistical analyses. According to variance analyses and mineralogical studies most of the heavy minerals in the Karkheh River sediments originate from three lithological units which are dominantly located in the upper parts of the basin and the Sanandaj-Sirjan zone. Estimation of heavy minerals show that total percent of bright heavy minerals (zircon, rutile, garnet and tourmaline) in the Karkheh sediments is more than 5% (63285.86 g/t) and dark heavy minerals (ilmenite, hematite, magnetite) in this sediments is more than 6% (7474.84 g/t). Based on the procedure suggested by Rose & Webb (1979) several high-potential areas were selected for garnet, zircon, ilmenite and rutile exploration in the Karkheh River sediments. Covariance coefficient shows close positive correlation for zircon and rutile minerals in all the samples and anomalous area. Garnet and magnetite show a constant distribution in the Karkheh River sediments.