Semi-detailed exploration of Torqabeh Gold deposit
Executive: A. Eqbali Zarch
Technical Executive: Behrooz Borna
The Torqabeh gold deposit is located 8 Km away from the west of Mashhad, in the north of Binalud Mountains. Au-Ore mineralization has occurred along two bands of metamorphic rocks in the biotite granite body, near the contact of intrusive body with phyllite, slate, schist, quartzite, and granitic gneiss that forms a fractured zone. Remnants of open and underground workings exit along the 800m of mineralized zone. There is evidence of two drilled holes in the area.
The result obtained from analyses of 268 samples collected from exploratory trenches shows up to 23.1 ppm Au in the quartzite rocks of the metamorphic belt. High Au content mostly observed in the quartzite fragments, in the fractured zone. Polished-section studies confirmed an exhalative genesis for the gold. It seems that the Paleozoic metamorphic rocks are the source rocks that influenced by biotite granite body intruded in the last stages of magmatism in the tectonic zone. Measurement of Ag and As content show a correlation between them and Au.
Based on the gold analysis result obtained from new trenches, outcrops and old excavations, the deposit was divided into 11 blocks. Average grade calculated for each block to estimate the possible reserve of deposit. Possible reserve of deposit is 330 Kg gold. The best surficial sections of deposit were exploited by ancients. Probably, the remained reserve is much more than calculations.