Identification of geochemical anomalies from the background using the Concentration-Perimeter fractal model (log-log C-P) in the Shirbit area (northeast of Ahar)

Siahcheshm, Kamal; Vahdati Helan, Azizeh; Alavi, Seyyed Gafur

doi:10.52547/esrj.10.1.206

Identification of geochemical anomalies from the background using the Concentration-Perimeter fractal model (log-log C-P) in the Shirbit area (northeast of Ahar)

Document Type : علمی -پژوهشی

Authors

¹ Assistant Professor, Department of Earth Sciences, Faculty of Natural Sciences, University of Tabriz

² MS.c in Economic Geology, Department of Earth Sciences, Faculty of Natural Sciences, University of Tabriz

10.52547/esrj.10.1.206

Abstract

The Shirbit polymetal prospect area is located in 30 km north-east of Ahar city within the Ahar- ore filed in around of Shivardagh batholith. Intrusion of granodiorite igneous bodies into the Eocene trachyte to andesite associated with pyroclastic interlayers caused widespread silicic, argillic and propylitic hydrothermal alteration associated with the Cu, Mo, Pb mineralization as quartz-sulfide (±oxide, carbonate, sulphate) vein and veinlets. Most of chalcopyrite, pyrite and molybdenite veins together with malachite, azurite and iron hydroxides were concentrated in the trachytic-andesitic units with silicic-argillic alteration. The turning point of this study includes investigating the possibility of log-log C-P method for separating geochemical anomalies of ore forming elements from the background, accurately determining the cut-off grade, decreasing the area of anomalies, and determining the number of stages of enrichment of elements in the study area compared to the multivariate statistical methods. For this purpose, 85 stream sediment samples taken from a systematic geochemical network were analyzed using ICP-MS method. In order to identify the susceptible mineralization areas by using of concentration-perimeter double logarithmic method, thee background values and anomalies were separated for each element in the region. Then, elemental anomaly maps were prepared and finally the distribution maps of the ore-forming elements were mapped and the relevant anomalies were distinguished. The results of using C-P fractal method indicates the presence of possible anomalies of Cu, Mo and Ti elements in the eastern, northeastern, and southwest parts of Shirbit area.

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