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Mineral Paragenesis and Ore‐Forming Processes of the Dongping Gold Deposit, Hebei Province, China
Author(s) -
Wang Dazhao,
Liu Jiajun,
Zhai Degao,
Carranza Emmanuel J. M.,
Wang Yinhong,
Zhen Shimin,
Wang Jiang,
Wang Jianping,
Liu Zhenjiang,
Zhang Fangfang
Publication year - 2019
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.12202
Subject(s) - paragenesis , geology , molybdenite , sphalerite , geochemistry , pyrite , galena , pyrrhotite , tetrahedrite , mineralogy , fluid inclusions , quartz , paleontology , metamorphic rock
The Dongping gold deposit is located near the center of the northern margin of the North China Craton. It is hosted in the Shuiquangou syenite and characterized by large amounts of tellurides. Numerous studies have addressed this deposit; the mineral paragenesis and ore‐forming processes, however, are still poorly studied. In this contribution, a new mineral paragenesis has been evaluated to further understand ore formation, including sulfides (pyrite, chalcopyrite, galena, sphalerite, molybdenite, and bornite), tellurides (altaite, calaverite, hessite, muthmannite, petzite, rucklidgeite, sylvanite, tellurobismuthite, tetradymite, and volynskite), and native elements (tellurium and gold). Molybdenite, muthmannite, rucklidgeite, and volynskite are reported for the first time in this deposit. We consider the Dongping gold deposit mainly formed in the Devonian, and the ore‐forming processes and the physicochemical conditions for ore formation can be reconstructed based on our newly identified ore paragenesis, that is, iron oxides → (CO 2 effervescence) → sulfides → ( f Te 2 / f S 2 ratio increase) → Pb‐Bi‐tellurides → (condensation of H 2 Te vapor) → Au‐Ag‐tellurides → (mixing with oxidizing water) → carbonate and microporous gold → secondary minerals → secondary minerals. The log f O 2 values increase from the early to late stages, while the f H 2 S and log f S 2 values increase initially and then decrease. CO 2 effervescence is the main mechanism of sulfides precipitation; this sulfidation and condensation of H 2 Te vapor lead to deposition of tellurides. The development of microporous gold indicates that the deposit might experience overprint after mineralization. The Dongping gold deposit has a close genetic relationship with the Shuiquangou syenite, and tellurium likely originated from Shuiquangou alkaline magmatic degassing.