Geochemical Survey in the 1:100000 sheet of Esfahan
Regional exploration on the scale 1:100000 is a fundamental exploration work for identification of mineral potentials. In this project, the 1:100000 sheet of Esfahan was explored by stream sediment geochemical method. The first section of report includes geochemical survey to preparation of anomaly maps. In the second part, the anomalies were controlled by sampling from heavy minerals, alterations and mineralized zones.
The 1:100000 sheet of Esfahan is located in the southwestern portion of the Esfahan Quadrangle, between 51 30' to 52 E and 32 30' to 33N.
Available lithologies include cretaceous limestones at northwest, northeast, southwest, south and center of the sheet. Most part of the sheet is covered by alluvial deposits of the Zayandehrud River. Mount Irankuh (2418) is the highest point in the sheet.
348 stream sediment samples were collected by four groups from the areas to be analyzed for the geochemical proposes. Sampling was done on the base of weight center of drainage basins. Each sample included 100 to 200 grams deposit that sieved by 80 mesh sieve and then dried, packed and sent for analysis.
For processing the data, we entered them into a dataset with lithology of upstream rocks. Censored data replaced with calculated values. Enrichment indexes calculated for six rock classes. These rock classes were used for preparing the anomaly maps of the area.
In the control phase we used heavy mineral sampling method to check the anomalies in the field. 85 heavy mineral samples were taken. After this step, each anomaly was modeled on the base of stratigraphy, host rock, age, alterations, geochemical parageneses, ore minerals in the heavy mineral study, structure and texture of mineralized zone and weathering products. Four final anomalies introduced in the Esfahan 1:100000 sheet.
Anomaly number 2- it is located in the 1:50000 sheet of Esfahan near the Tappeh-Sorkh mine of Irankuh. This zone correlates with sedimentary manganese and polymetallic vein deposits.
Anomaly number 3- it is located in the 1:50000 sheet of Esfahan near the Kolah Darvaze mine. This zone correlates with Mississippi lead-zinc, Appalachia, SEDEX and massive sulfide Besshi type deposits.
Anomaly number 1- it is located in the 1:50000 sheet of Esfahan near the south of city Esfahan. This zone correlates with sandstone-hosted lead-zinc, massive sulfide Besshi type, SEDEX and Appalachia type deposits.
Anomaly number 4- it is located in the 1:50000 sheet of Shahinshahr near the southwestern cornet of the sheet. This zone correlates with sandstone-hosted lead-zinc, Mississippi lead-zinc and massive sulfide Besshi type deposits.