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Rb–Sr Dating of Gold‐bearing Pyrites from W ulaga Gold Deposit and its Geological Significance
Author(s) -
Wang Yongbin,
Zeng Qingdong,
Liu Jianming
Publication year - 2014
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/rge.12040
Subject(s) - pyrite , geology , geochemistry , chalcedony , breccia , hydrothermal circulation , mineralization (soil science) , mineralogy , calcite , paleontology , soil science , soil water
Wulaga epithermal gold deposit is located in northeast C hina. Gold mineralization mainly occurs within the crypto‐explosive breccia belt of subvolcanic intrusion. Constraints on the precise timing of mineralization are of fundamental importance for understanding the ore genesis of the W ulaga gold deposit and its mineralization potential. Three hydrothermal stages have been identified: the early veiny quartz–euhedral pyrite stage; the fine pyrite–marcasite–gray or black chalcedony stage; and the late carbonate–pyrite stage. The Rb–Sr dating of gold‐bearing pyrites from the fine pyrite–marcasite–gray or black chalcedony stage is 113.8 ± 4.4 Ma with an initial 87 Sr/ 86 Sr ratio of 0.706346 ± 0.000019. The age of the gold deposit is consistent with the age of ore‐bearing volcanic (109–113 Ma) and subvolcanic intrusion (103–112 Ma) within the error limits, and the pyrite initial ratio has an identical value of 87 Sr / 86 Sr to subvolcanic intrusion (0.705547 ± 0.000012). These indicate that crystallization of the wall rock and epithermal gold mineralization was coeval and likely cogenetic. Moreover, a lot of epithermal gold deposits that formed in E arly C retaceous volcanic and subvolcanic intrusions have been discovered in recent years in H eilongjiang province. Combined with the studies of tectonic and magmatic activities, we propose that the formation of the W ulaga gold deposit might be caused by the heated circum‐flow water related to the volcanic–subvolcanic intrusive hydrothermal event triggered by the ancient subduction of the I zanagi plate in the E arly C retaceous.