Disseminated Gold–Sulfide Mineralization in Metasomatites of the Khangalas Deposit, Yana–Kolyma Metallogenic Belt (Northeast Russia): Analysis of the Texture, Geochemistry, and S Isotopic Composition of Pyrite and Arsenopyrite

At the orogenic gold deposits of Yana–Kolyma metallogenic belt (northeast Russia) both Au–quartz-sulfide mineralization with native and disseminated sulfide invisible Au developed. The textural mineralogical-geochemical features, isotope-geochemical characteristics gold-bearing sulfides from proximal metasomatites, possible forms occurrence in pyrite arsenopyrite have been studied using electron microprobe, atomic absorption, LA-ICP-MS trace element, isotope analysis, computed microtomography. Four generations (Py1, diagenetic; Py2, metamorphic; Py3, metasomatic; Py4, veined) two (Apy1, Apy2, identified at Khangalas deposit. In most common are Py3 Apy1. Studying their chemical composition makes it to identify features distribution patterns typochemical elements arsenopyrite, establish nature relationship between these elements. Apy1, structurally bound (solid solution) Au+ prevails, isomorphically entering crystal lattice or its defects. Isotope hydrothermal (δ34S = −2.0 −0.6‰) indicate that mantle/magmatic sulfur was involved formation deposit, though participation host rocks Verkhoyansk clastic complex cannot be ruled out. deposit has much other belt, this point view, results obtained will help better reveal potential understand origin.