Tectonic Transformation and Metallogenesis of the Yanshan Movement during the Late Jurassic Period: Evidence from Geochemistry and Zircon U-Pb Geochronology of the Adamellites in Xingcheng, Western Liaoning, China
| Autor: | Chen-Yue Liang, Yan Yang, Erlin Zhu, Xiao Zhou, Pengyue Hu, Changqing Zheng |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
geography
geography.geographical_feature_category lcsh:Mineralogy lcsh:QE351-399.2 010504 meteorology & atmospheric sciences Subduction Volcanic arc Yanshan Movement Paleo-Pacific plate Partial melting Geochemistry Geology Crust 010502 geochemistry & geophysics Geotechnical Engineering and Engineering Geology 01 natural sciences magmatic activity Craton Magmatism Geochronology mineralization North China Craton (NCC) 0105 earth and related environmental sciences Zircon |
| Zdroj: | Minerals Volume 9 Issue 9 Minerals, Vol 9, Iss 9, p 518 (2019) |
| ISSN: | 2075-163X |
| DOI: | 10.3390/min9090518 |
| Popis: | The Yanshan Movement occurred mainly during the Middle-Late Jurassic, and gave rise to NE trending structures, magmatic events, volcanism and mineral resources. The transformation and evolution of the movement during the Middle-Late Jurassic were investigated from the rock assemblage, geochemistry, and chronology in adamellites which were exposed in the Xingcheng area, western Liaoning. Two types of adamellites were recognized&mdash biotite adamellites with the formation age of 172&ndash 168 Ma and garnet-bearing adamellites of 158&ndash 152 Ma. All the samples of the two types of adamellites displayed enriched characteristics with high content of SiO2 (66.86&ndash 75.55 wt.%) and total alkali (Na2O + K2O = 7.56&ndash 8.71 wt.%), high large ion lithophile element (LILE: K, Rb, Sr), and low high field strength element (HFSE: Ce, Ta, P, Ti). The biotite adamellites belong to metaluminous-peraluminous I-type granites, and show volcanic arc granite characteristics, and were formed by partial melting of the ancient crust in the compressional setting that resulting from the subduction of the Paleo-Pacific plate beneath the north margin of the North China Craton (NCC). The garnet-bearing adamellites are also metaluminous-peraluminous I-type granites, with characteristics of both the compressional and extensional regimes, which were formed at the middle-late stages of the continuing subduction of the Paleo-Pacific plate, while simultaneously, the frontal side of the subduction slab began to roll back, leading to an extensional environment. Combining with regional geophysical studies and our petrological and geochemical studies, we propose that the eastern segment of the northern margin of NCC may have been controlled by the Paleo-Pacific tectonic domain at the latest in the Middle Jurassic, while the initiation of the tectonic regime from a compressional to an extensional environment was during the Late Jurassic (158&ndash 152 Ma) as a response of the Yanshan Movement. Simultaneously, geochronological statistics of the ore deposits in western Liaoning show that the Mesozoic endogenetic metalliferous deposits formed in a compressive environment influenced by the subduction of the Paleo-Pacific plate, similar to the magma events in ages, and the magmatism provided the thermodynamic condition and the source of metallogenic hydrothermal fluid for mineralization. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |