Abstract <p>The results of a study of the isotopic composition of sulfide sulfur from different-age orogenic gold mineralization of the Marinskoye deposit of the Allakh-Yun zone of the Okhotsk-Koryak belt are presented. The variations in the δ³⁴S value range between –16.2 and +34.1‰. The δ³⁴S values of sulfides from the Late Jurassic early orogenic gold mineralization (pyrite-3.1, pyrite-3.2, arsenopyrite, and galena-1) change between –16.2 and –4.3‰ with a decrease from early to late mineral associations. Extremely wide variations in the δ³⁴S value between –10.5 and +34.1‰ (pyrite-4.1, pyrite-4.2, galena-2, sphalerite, and chalcopyrite) are determined in sulfides of successively formed mineral associations of the Aptian late orogenic mineralization. Sulfur in pyrite-quartz metasomatic and pyrite-sericite-quartz vein mineral associations (δ³⁴S between +3.0 and +34.1‰) could have been borrowed from stratiform lead-zinc mineralization and be a product of thermochemical sulfate reduction process in a closed system. The performed studies suggest that sedimentary strata of different ages were the main source of sulfide sulfur at the Marinskoye deposit.</p>