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Stable Isotope Study of the Langshan Polymetallic Mineral District, Inner Mongolia, China
Author(s) -
DING Ti–Ping,
JIANG Shao–Yong
Publication year - 2000
Publication title -
resource geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 43
eISSN - 1751-3928
pISSN - 1344-1698
DOI - 10.1111/j.1751-3928.2000.tb00053.x
Subject(s) - geology , geochemistry , metamorphism , proterozoic , meteoric water , metamorphic rock , sedimentary rock , isotope geochemistry , isotope , mineral , hydrothermal circulation , mineralogy , paleontology , tectonics , chemistry , physics , quantum mechanics , organic chemistry
A comprehensive stable isotope investigation was carried out to clarify the geneses of the ore deposits in the Langshan Pb‐Zn mineral district. The lead isotope study shows that these deposits were probably formed from 2. 0 to 1. 5 Ga, and were deformed and metamorphosed 1. 45 Ga. Ore lead could be a mixture of mantle lead and crustal lead. The C and S isotope results indicate that these deposits were precipitated in closed or semi‐closed rift basins, and the source of sulfur might be Proterozoic ocean sulfate. The H and O isotope results indicate that the δD and δ 18 O values of rocks were changed by water‐rock interaction during metamorphism and hydrothermal alteration. The scale of δD and δ 18 O shift of rocks reflects the grade of metamorphism and alteration as well as the water‐rock ratios. However, the water‐rock ratios in the metamorphic processes of Langshan mineral district were relatively low, and the source of water during metamorphism is suggested to be ancient meteoric water. Based on isotopic results and the geological background, it is concluded that these deposits may belong to Proterozoic sedimentary exhalative (SEDEX) type.