Tin-Tungestin exploration in the Khaku area, Hamedan
Manoochehr Soheili, Soleyman Kosari
A parallelogram shaped area that is 7 square kilometers, located 6 Km away from the south of Hamedan and a kilometer away from west of the Khaku village. In addition to granitic rocks that exposes in the most of the area, the composition and mineralogy of other rock units are in relation to the granitic intrusion. The Alvand granite in the south and west of Hamedan has lenticular outcrop that is 40 km long and 5 Km wide. This porphyroid granite has large alkali-feldspars and plagioclases up to 10 Cm. It is a S-type granite related to the intrusion of mafic rocks especially, olivine gabbro. These rocks caused the partial melting of subducting oceanic crust and formation of felsic magma. The age of body is 63-80 Ma by Rubidium-Strontium method.
In the contact of granite and andalusite-cordierite hornfels, veins, dykes and tourmaline-bearing pegmatites have occurred that highlight the last stage of magmatism. Dykes are ore than 100m in some portions.