Geochemical exploration in the Qarachaman sheet of 1:100000
By: Nastaran Ebrahimi, Maryam Dehghan, Reza Hosseinzadeh, Behzad Barati, Hossein Hematian
This project is about geochemical survey in the 1:100000 sheet of Qarachaman. It is located between 37 30' to 38 E and 47 to 47 30' N, in the Azarbaijan-e Sharqi Province. The sheet consists of four 1:50000 sheets including Abarghan, Torkaman, Siyahchaman, and Dordoran.
The 1:100000 sheet of Qarachaman is located in the Miyaneh 1:250000 quadrangle that includes Eocene volcano-sedimentary rocks of the Orumiyeh-Dokhtar zone. Available rocks involve post-Eocene volcanic and sedimentary rocks that can divided into two northern (Bozgush range) and southern (Shahrichay-Qarachaman) sections.
Geochemical survey was done through sampling from stream sediments, on the base of 1:100000 topography map of the area. Each sample consisted of 100 to 200 grams alluvial deposit that sieved with 80-mesh sieve. Sample points were recorded by GPS. After converting the samples to 200 mesh, totally, 745 samples were analyzed for 44 elements.
Obtained data processed to calculate the enrichment index of elements. Several geochemical anomalies identified to be checked in the field. We used heavy mineral and mineralized rock sampling for controlling the geochemical anomalies. About 100 heavy mineral samples were studied for this sheet. In the next step, we modeled those anomalies that verified as mineralization zones.
Applied data for ore deposit modeling of anomalies include exposed stratigraphy, host rock, age, probable alterations, geochemical parageneses, ore minerals in the heavy mineral samples, structure and texture of host rock, structure and texture of mineralized zone, alteration products and tectonic setting.
11 favorable anomalies were introduced and prioritized for further studies. Four anomalies have first priority, two anomalies have second priority and two anomalies have third priority. Also, anomalies I, III and XI are invaluable. The report contains detailed description of anomalies.