Contribution of crustal and mantle sources to genesis of Sn, B and Pb-Zn deposits in South Sikhote-Alin subprovince (Russian Far East): evidence from high–precision MC-ICP-MS lead isotope study

Abstract South Sikhote-Alin metallogenic subprovince (SSAP) is located in the southern part of the Sikhote-Alin orogenic belt. It encompasses more than one hundred well-known deposits and occurrences of boron, tin, lead, and zinc. These deposits have been genetically related to the Late Cretaceous and Paleocene granitoid magmatism. Pb isotope composition was measured using the MC-ICP-MS method in 20 SSAP deposits. Pb isotope ratios (48 samples of galena) vary within narrow limits: 206Pb/204Pb ranges from 18.321 to 18.474, 207Pb/204Pb - 15.608 - 15.655, and 208Pb/204Pb 38.601 - 38.796. The high degree of homogeneity of the Pb isotope composition and absence of correlations between the lead isotope characteristics of the deposits, on the one hand, and the age and type of ore mineralization, on the other, indicate the presence of a regional uniform Pb source for all the SSAP deposits. The results of Pb-Pb studies of the different rocks of the SSAP suggest that the source was most likely the Mesozoic sedimentary sequences of the Sikhote-Alin accretionary complexes. In turn, individual lead isotope characteristics of the SSAP deposits are caused by varibale contribution of mantle source to the overall balance of lead.