Exhumation history of the Sanshandao Au deposit, Jiaodong: constraints from structural analysis and (U-Th)/He thermochronology

Autor: Xuan Liu, Hong-Rui Fan, Noreen J. Evans, Kui-Feng Yang, Martin Danišík, Brent I. A. McInnes, Ke-Zhang Qin, Xue-Feng Yu
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Scientific Reports, Vol 7, Iss 1, Pp 1-12 (2017)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-017-08103-w
Popis: Abstract The Sanshandao gold deposit contains an estimated Au resource of >1500 tons, however little is known about the history of exhumation, and the magnitude of displacement on the ore-hosting fault. Structural measurement revealed two phases of normal and one phase of sinistral movement on the fault. Despite of intra-sample dispersions, (U-Th)/He ages from two sub-vertical profiles show decreasing trends from the surface down to −3560 m (zircon: 123 Ma to 55 Ma; apatite 103 Ma to 0.3 Ma). Over-dispersion of AHe ages likely reflects the presence of undetected inclusions. According to the age-depth pattern, we infer that the deposit underwent an early phase of rapid cooling in the late Early Cretaceous, which was followed by a short period of thermal stagnation and a revived rapid cooling between 75 Ma and 55 Ma in response to a combined effects of late normal movement and erosion. Since the Eocene, the deposit has experienced a slow monotonic cooling. Exhumation magnitude estimates suggest that the deposit have been denudated > 5.1 km. The two phases of normal displacement along the fault occurred in the late Early Cretaceous and Late Cretaceous to Paleocene, leading to a total offset magnitude of 0.5–2.3 km.
Databáze: Directory of Open Access Journals
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