S isotopic geochemistry, zircon and cassiterite u–pb geochronology of the Haobugao Sn polymetallic deposit, southern Great Xing’an Range, NE China

Abstract

The southern Great Xing’an Range (SGXR) is the most important tin polymetallic metallogenic belt in north China. The lack of previous research on the genesis of the tin mineralization, especially its exact age, prevents development of a deep understanding of tin deposits in this area. Haobugao Sn polymetallic deposit is a large skarn type deposit in the Huangang-Ganzhuermiao Sn-Fe-Cu-Pb-Zn-Ag metallogenic belt in the SGXR. The ore body occurs in the contact zone between a Yanshanian intrusion and Permian Dashizhai Formation marble. δ34SV-CDT values of sulfides from the Haobugao Sn polymetallic deposit range from −4.7 to +3.5‰, with an average of −0.65‰, and these values strongly indicate a deep magmatic source for the sulfur in the ore minerals of the deposit. In this paper, we also report the results of LA ICP-MS U-Pb dating of tin mineralization in No. I ore body and of the underlying granite. Cassiterite from No. 1 ore body deposited at 139 ± 0.6 Ma, and the closely associated granite has an age of 142.9 ± 1.6 Ma. The similar ages indicate that the tin mineralization was produced by Early Cretaceous magmatic hydrothermal activity. These results, together with the ages of other tin deposits and related granites, indicate extensive granitic magmatism and tin mineralization during the Early Cretaceous in the southern segment of the Great Xing’an Range.