Systematic Geochemical Exploration in the Fereidunshahr sheet (1:100000)
Dr. Mahmoud Mehrparto
Mr. Mostafa Mostan
Kan- Iran Consulting Engineers
systematic geochemical exploration studies in the Fereidunshahr sheet was the central issue of a contract between Kan-Iran Consulting Engineers and the GSI. The goal of project is the systematic geochemical studies at scale 1:100000 in accordance to existing standards of geochemical studies. In order to achieve the above objectives experts during a planned program and using the available information, including aerial geophysics and geological map, the sampling points designed on the 1:50000 topographic maps. 800 stream sediment samples with 30 duplicate samples were taken with granulometry of 80 mesh. The samples were sent to the Amdel laboratory of Australia for analyzing by ICP-MS method. After receiving the results and data processing preliminary anomalies were determined.
The second phase includes the filed control of anomalies by taking heavy minerals and rock samples from the main branches. Totally 107 heavy mineral samples and 10 duplicate samples of heavy minerals were taken from the preliminary anomalies. Map number one shows the places of heavy mineral samples with other samples for Fereidunshahr 1:100000 sheet. In this project, also we took 35 mineralized samples of rock. All of these samples were sent to the ALS Chemex laboratory in Australia. After preparing the results of rock samples and studying the heavy minerals and combining them together, appropriate anomalies identified in terms of importance and priority.
More than seventy percent of the rock units in the region are sedimentary deposits and the rest is of the old basement stones of the metamorphic Sanandaj-Sirjan zone. Composition of metamorphic rocks includes amphibole schist, gneisses and crystalline limestone, while the sedimentary rocks generally involve Jurassic - Cretaceous and sometimes Permian rocks.
Structural units and tectonic elements along the northwest - southeast and always follow the trend of the Zagros fault zone. Despite the presence of Zagros fault, there is less important alteration in the region.
Metamorphic rocks in part of the tectonic units belonging to the Sanandaj-Sirjan contain iron bearing rocks that can be considered as the product of Metamorphism. In some parts the rock samples contains very low levels of gold with lead and zinc anomalies. However, there were no significant anomalies in the Fereidunshahr sheet.