Geochemical studies, mineralization and mineral potential of Tafresh area, the Iran-Markazi

Abstract

The study area is part of the Urumieh–Dokhtar volcanic arc that a large part of its surface is covered by extrusive Igneous rocks (tuff, intermediate lavas and ignimbrites sheets), plutonic igneous (diorite and granodiorite) and semi-deep stones (dyke and sill). Studied samples are situated in calc-alkaline domain of magmatic series diagrams. Harker diagrams show the fractional crystallization of Clinopyroxene, amphibole, plagioclase, alkali feldspars and opaque minerals (ilmenite Titano-magnetite, ilmenite and rutile). In spider diagrams, light rare earth elements (LREE) are enriched compared to heavy rare earth elements (HREE), and HFS elements (Ti, Nb) show negative anomaly and LFS elements (Cs, K, Pb) show positive anomaly, showing that it is a distinct characteristic of subduction zones. Skarns of the area mainly are of exoskarns and are rich in plagioclase, microcline, amphibole, biotite and epidote. Skarn is enriched of iron, copper, molybdenum, vanadium, lead, zinc and silver. Deposits of barite in the area show characteristics of volcanic-sedimentary barites and are associated to ore-bearing hydrothermal solutions. Using satellite images and processing information, four areas with high mineral potential are identified in the area.