Geochronological and Geochemical Constraints on the Formation of the Giant Zaozigou Au-Sb Deposit, West Qinling, China

Autor: Hao-Cheng Yu, Chang-An Guo, Kun-Feng Qiu, Duncan McIntire, Gui-Peng Jiang, Zong-Yang Gou, Jian-Zhen Geng, Yao Pang, Rui Zhu, Ning-Bo Li
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Minerals, Vol 9, Iss 1, p 37 (2019)
Druh dokumentu: article
ISSN: 2075-163X
DOI: 10.3390/min9010037
Popis: The Zaozigou Au-Sb deposit has been controversial in its genesis and remains one of the most difficult ore systems to fully understand in West Qinling. The mineralization shows a broad spatial association with Triassic dikes and sills, which were previously thought to be genetically related to mineralization. Our U-Pb zircon dating in this contribution indicates that the ore-hosting porphyritic dacites were formed at 246.1 ± 5.2 Ma and 248.1 ± 3.8 Ma. The magmatic zircons yield εHf(t) values ranging from −12.5 to −8.9, with corresponding two-stage model ages of 2.08 to 1.83 Ga. The magma therefore could be derived from partial melting of Paleoproterozoic crustal materials. The ore-hosting porphyritic dacites have low oxygen fugacity, with ΔFMQ ranging from −4.61 to −2.56, indicating that magmas could have been sulfide-saturated during evolution in deep chambers and precluding the possibility that metals were released from the melt. Zaozigou exhibits characteristics widespread volcanics, massive sulfide mineralization, rare reduced mineral assemblage and discrete alteration zones which are not typical of reduced intrusion-related or porphyry gold systems. We propose that the spatially-related Triassic porphyritic dacite and dike swarm is not genetically related to the ore formation of Zaozigou Au-Sb deposit.
Databáze: Directory of Open Access Journals
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