Parameters for the Formation of the Dobroe Gold Deposit (Yenisei Ridge, Russia): Evidence from Fluid Inclusions and S–C Isotopes

The Dobroe deposit with 10 t gold reserves is one of the gold mines located within the Yenisei Ridge Orogenic Belt. The ore-forming conditions of orogenic gold deposits are have recently been widely discussed. A comprehensive study of fluid inclusions revealed that the Dobroe gold deposit was formed by water–carbon dioxide and carbon dioxide–hydrocarbon fluids within a temperature range of 180 to 360 °C, a pressure range of 0.8 to 1.3 kbar, and a salinity range of 1.5 to 15.0 wt.% (NaCl-equiv.). Gas chromatography–mass spectrometry showed that ore-forming fluids consisted of H2O, CO2, hydrocarbons, nitrogenated, sulfonated, and chlorinated compounds. The distribution patterns of δ13C in fluid inclusions (−11.3‰–−3.6‰) and δ34S in sulfides (1.9‰–17‰) of the Dobroe deposit indicate a crustal source for ore-bearing fluids.