S.I. TURCHENKO (IPGG RAS)

Sulfur release during rock metamorphism in the Earth’s crust: application to gold deposits genesis

Understanding of sulfur source during metamorphic rock reworking is important for understanding the complete cycle of ore genesis in sulfide deposits. The T­P limits of pyrite­pyrrhotite transformation, which released sulfur as a result of metamorphism, are discussed in the paper. Results of the study show that most of sulfur is released in a narrow interval of temperature that transforms chlorite to muscovite and simultaneously releases H2O. Most of sulfur and water for hydrothermal fluids, when gold ore deposits can also be formed, are generated under metamorphism from greenschist to the lower­-temperature part of amphibolite facies. Tectonic positions for forming such ore deposits and role of carbonic-­sulfide sediments and deformations also are shown.
Keywords: sulfur release, rocks metamorphism, sources of sulfur, water, gold, tectonic positions of gold deposits.