Pioneer studies of ores from the Solnechnoe tin deposit (Omsukchan district, Magadan region) located near the endocontact of the Levo-Omsukchan leucogranite massif are focused on their mineralogical and geochemical characteristics. The tin-bearing granites of the Omsukchan Complex are classified as A‑type. Under the conditions of the Balygychan–Sugoy continental rift, they acquire the high contents of K2O (>4%) and Na2O (>3%), which are characteristic of porphyry intrusions specialized in Cu. The high concentrations of Cu and a wide range of copper minerals were identified in ores of the deposit: chalcocite, covellite, chalcopyrite, stannite, gyrite, bournonite, cuprite, and luzonite (Cu3AsS4)—a typical mineral of the porphyry copper system. Bismuth (Bi) minerals (bismuthinite, native bismuth, galenobismuthite) and Bi-bearing galena with a bismuth concentration up to 4.5 wt % are present. ICP-MS studies showed that the ores are enriched in a fairly wide range of trace elements (based on the enrichment factor): As, Bi, Ag, Au, Sb, Pb, In, Cd, Cu, W, Sc, Sn, Zn, Y, Be, Mo, Li, REE, U, and Co. The enrichment factors vary from a few (Y, Be, Mo, Li, REE, U, and Co) to tens (W, Sc, Sn, and Zn), hundreds (Sb, Pb, In, Cd, and Cu) and thousands (As, Bi, Ag, and Au) times. The copper content varies from 0.001 to 0.8%, and the gold content, from 1.26 to 6.84 ppm. ΣREE ranges from 101.9 to 424.29 ppm, averaging 237.2 ppm. The REE distributions are similar to those of the leucogranites of the Omsukchan Complex and are characterized by a nearly horizontal pattern in its heavy part (LaN/YbN = 0.61–6.84) and a deep trough at Eu (Eu/Eu* = 0.23–0.52). This indicates that the REE composition in the ores is inherited from the host rocks. Indicator values of Ce/Ce* (0.72–1.19) and Eu/Eu* (0.23–0.52) are typical of oxidizing conditions during mineralization process. It was proposed that hybridization and melt mixing occurred during the formation of volcanoplutonic complexes in the aborted Balygychan–Sugoy rift. The composition of the Levo-Omsukchan leucogranites could have been significantly influenced by the Askoldin ultrapotassic rhyolites, which enriched the granites in K2O and Na2O, as well as by the granitoids of the Nayakhan Complex and deep ultramafic rocks from the rift base, with their peculiar copper geochemical profile as an additional source of copper. Thus, conditions were created for the formation of the porphyry copper mineralization. The information presented in the paper is of great practical significance for regional forecasting–metallogenic considerations.
Савва et al. (Mon,) studied this question.