A Case History of Applying In situ Analysis of the Sulfur Isotopic Compositions of Sulfides from Ores of the Largest Deposits in the Bodaibo Synclinorium (Eastern Siberia)

Resumo

The experience of applying the laser ablation technique to study the sulfur isotopic compositions of pyrite and arsenopyrite samples from gold deposits of the Baikal–Patom highland is discussed. The experimental procedure is described. All studied samples were found to display δ³⁴S and δ³³S values in strict compliance with the law of mass-dependent sulfur isotope fractionation. Regular lightening of the sulfur isotope composition in the course of crystal growth for pyrites from the Sukhoi Log deposit and the isotopic homogeneity of pyrite and pyrrhotite from the Golets Vysochaishii deposit were established. The conclusion that the sulfur isotopic homogeneity of sulfides in the ores occurs probably owing to metamorphism within the Mama–Oron belt was made.