Origin determination of alluvial sand deposits around the Dashkasan gold mine, northeast of Qorveh

Authors

1 Geology department, Isfahan university, Isfahan

2 Department of Geology, University of Isfahan

3 Department of Geology- University of Isfahan

10.22055/aag.2025.48255.2480

Abstract

The Shour river flows in northeast of Qorveh city, the Kurdistan province. Sedimentary, igneous and metamorphic rocks outcrop in the river catchment area. The hydrothermal mineralization with Miocene age has occurred in the igneous massifs of this region. In order to study and determine origin of the alluvial sand sediments, 31 sediment samples were collected from the Shour river and its tributaries (the Dashkasan and Neyband rivers) and granulated by wet and dry sieving methods. Sands in the 120-60 mesh class were selected for microscopic studies, chemical analysis and provenance determination of the sediments. Based on the microscopic studies, frequencies of the carbonate, volcanic and metamorphic rock fragments, quartz and feldspar minerals, non-opaque and opaque heavy minerals were identified and their frequency was determined. Heavy mineral constituents of 7 samples were separated by bromoform and according to the study of thin-polish sections include hornblende, pyroxene, magnetite and hematite, biotite, epidote, realgar, orpiment, goethite and pyrite in their order of frequency. The sand grains are dominantly semi-angled to semi-rounded and have low to medium sphericity. Titanium, manganese, calcium, phosphate, strontium and thorium have higher frequency than the upper crust in most samples. The samples with more carbonate components have fewer rare earth elements. The studied sediments show slight weathering in the source rock based on the ICV and CIA indices. Climate of the sediment source area is semi-arid and cold based on the modal analysis consistent with results of the ICV and CIA indices.

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