Petrology and mineralization of intrusive bodies of the Sehezar Valley of Tonokabon for mineral potential study

Sehezar area is located in southern Tonokabon in Mazandaran province, north of Iran, near the Tarom – Hashdtjin belt. The existence of granitoid masses in the region can be important in terms of mineralization potential. The geological complex exposed in the area mainly consists of Paleozoic to Cenozoic lithologic units. In this study, a number of samples were used for microscopic and petrographic studies, as well as some samples of granites in the area for the classification of rocks. According to the studies performed on polished sections, minerals of pyrite, chalcopyrite and magnetite were observed. The textures found in thin sections are granular, Hyaloporphyritic, and Vitrophyric. The presence of porphyry textures indicates the simultaneous intrusions with volcanics and clastics originating from them. The major minerals in the region include quartz, K-feldspar, and plagioclase, and in some cases, hornblende, biotite, and pyroxene appear as the major mineral. The minor minerals found in the samples include sphene, pyroxene, iron oxides, apatite, and opaque minerals. Petrographic studies showed that the intrusive rocks of the region are of granite, granodiorite, syenite to quartz-syenite and quartz-monzonite. The magma in this area is in the domain of alkaline to calc-alkaline series and is a magnesian series and in the domain of metaluminous to peraluminous. The granites of the studied area are of peraluminous type and have a tectonic setting of the active continental margin and are I-type. Variogram studies showed that the spherical model is the best fitted model, and the spatial correlation range for the three elements of Au, Cu and Fe are approximately 350 m. Evaluating the results of geostatistics by calculating the root mean square error (RMSE) and calculating the mean absolute error (MAE) indicates the acceptable accuracy of variogram model. According to the Meinert diagrams and spatial correlation of the elements, it is concluded that these masses can be related to the deposits of iron-gold-copper.