关键词: 闪锌矿Rb-Sr 测年, 成矿物质来源, 地质意义, 锌矿, 升天坪

Abstract: Shengtianping zinc deposit is located in Xuefengshan region, which is at the southeastern part of Yangtze Block. It is a
medium-size zinc deposit that occurs in the Doushantuo Formation in western Hunan Province. In this study, Rb, Sr isotope analysis
were carried out on the main metallogenic period of sphalerite using the isotopic dilution method. Rb-Sr analyses yield an isochron age
of 490 Ma and the initial strontium isotopic composition of 87Sr/86Sr is 0.71235. The isochron age represents the timing of the main
mineralization stage of the deposit, indicating that the deposit was formed in the late Cambrian and the mineralization occurred in the
middle Caledonian. The characteristics of the sphalerite initial strontium isotope ratios reflect the far-field effect of the collisions of
surrounding blocks, which provided a driving force for the hydrothermal mineralization, and the Caledonian tectonism plays an
important role in the formation of the Shengtianping zinc deposit. The Shengtianping zinc deposit is strictly strata-bound, and the
deposit belongs to the sedimentary-transformation type of strata-bound ore deposit.

Key words: Rb-Sr dating of sphalerites, ore-forming materials source, geological significance, zinc deposit, Shengtianping