Geology, Mineralogy and Properties of hydrothermal fluid in Torghabeh Au-deposit, Mashhad

Category Engineering Geology
Group GSI.IR
Location 23th symposium on geosciences
Holding Date 05 May 2008

      Torghabeh Gold deposit is located 5 Km south of Mashhad. Mineralization is found within a sheared zone. This area is part of collision zone formed during Late Paleozoic time due to collision between Iranian plate and Turan Plate. Tonalite (Early Mesozoic age) intruded low grade regional metamorphosed rocks of Late Paleozoic And different types of schists were formed around the contact. Sheared zones cut all of the exposed rocks, therefore mineralization is younger than these rocks. Gold mineralization was associated with Silica rich fluid that has temperature about 350?C and reduction and basic condition. The width of mineralization is between 0.4 to 2.5 meter. Main minerals are quartz, pyrite, arsenopyrite, pyrrhotite and gold which are found mainly as disseminated. Gold grade is varies between 0.5 to 56 ppm and in average is less than 5 ppm. This deposit is a type of orogenic lode gold deposit