Lyubavinskoe Gold Deposit (Eastern Transbaikalia): Sources of the Formation and Petrogeochemical Features of Rocks and Ores

The Lyubavinskoe gold deposit is controlled by the submeridional deep tectonic zone. In this zone, ore veins closely associate with small Mesozoic granodiorite stocks, porphyry diorite, and lamprophyre dykes with a predominant sublatitudinal orientation. According to the geochemical patterns, these intrusions are similar to adakite. The proportion of the oxygen and strontium isotopes in granodiorite provides evidence for their formation as a result of the processes of mantle–crust interaction. The calculated values of δ¹⁸O_H2O in ore-bearing quartz range from +4.89 to +9.59‰, which corresponds to a hydrous fluid of magmatic origin. This is supported by the sulfur isotope composition of sulfides (δ³⁴S from 07 to 6.7‰) corresponding to the hydrothermal orogenic deposits.