Kai Weng , Yunpeng Dong , Zhongping Ma , Kai Cao , Yongwei Gao
{"title":"Petrogenesis of the Bastielieke W-mineralized granitic pluton in the Altai orogen, NW China","authors":"Kai Weng , Yunpeng Dong , Zhongping Ma , Kai Cao , Yongwei Gao","doi":"10.1016/j.jseaes.2024.106175","DOIUrl":null,"url":null,"abstract":"<div><p>Granitic magmatism of the Altai orogen is the key to understanding the tectonic evolution and metallogeny in the Central Asian Orogenic Belt (COAB). In this paper, we conducted comprehensive petrological, geochronological and geochemical investigations on the Bastielieke granitic pluton in the Altai orogen. Zircon U–Pb dating shows an emplacement age of 278–270 Ma for the pluton. Granites of the Bastielieke pluton have S-type granitic affinity and have Zr + Nb + Ce + Y contents (76.6–272 ppm), A/CNK ratios > 1.1, and K<sub>2</sub>O > Na<sub>2</sub>O. The low ε<sub>Nd</sub>(<em>t</em>) (−2.8 to + 2.9) and high ε<sub>Hf</sub>(<em>t</em>) (+7.6 to + 15.9) values with Nd-Hf isotope decoupling, invariable Pb isotopes, and moderate zircon δ<sup>18</sup>O<sub>V-SMOW</sub> values suggest crustal recycling of sedimentary rocks in a syn- to post-collision setting. In addition, the pluton is spatially related to the tungsten (W) deposit and also temporally consistent with the mineralization age of 284 ± 6 Ma, indicating a genetic link between the Early Permian magmatism and mineralization in Bastielieke. Furthermore, the source rocks of the pluton which are sedimentary rocks and abundant in W, provide the material basis for the initial enrichment of W in primary magmas. Given high Rb/Sr (>3) and low K/Rb ratios (<2<!--> <!-->0<!--> <!-->0), we interpret that the pluton has experienced high differentiation. Our studies propose that the termination of the subduction-accretion of the Paleo-Asian Ocean and the initiation of a syn- to post-collision regime for the Altai orogen are probably at the Early Permian.</p></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Asian Earth Sciences","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1367912024001706","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Granitic magmatism of the Altai orogen is the key to understanding the tectonic evolution and metallogeny in the Central Asian Orogenic Belt (COAB). In this paper, we conducted comprehensive petrological, geochronological and geochemical investigations on the Bastielieke granitic pluton in the Altai orogen. Zircon U–Pb dating shows an emplacement age of 278–270 Ma for the pluton. Granites of the Bastielieke pluton have S-type granitic affinity and have Zr + Nb + Ce + Y contents (76.6–272 ppm), A/CNK ratios > 1.1, and K2O > Na2O. The low εNd(t) (−2.8 to + 2.9) and high εHf(t) (+7.6 to + 15.9) values with Nd-Hf isotope decoupling, invariable Pb isotopes, and moderate zircon δ18OV-SMOW values suggest crustal recycling of sedimentary rocks in a syn- to post-collision setting. In addition, the pluton is spatially related to the tungsten (W) deposit and also temporally consistent with the mineralization age of 284 ± 6 Ma, indicating a genetic link between the Early Permian magmatism and mineralization in Bastielieke. Furthermore, the source rocks of the pluton which are sedimentary rocks and abundant in W, provide the material basis for the initial enrichment of W in primary magmas. Given high Rb/Sr (>3) and low K/Rb ratios (<2 0 0), we interpret that the pluton has experienced high differentiation. Our studies propose that the termination of the subduction-accretion of the Paleo-Asian Ocean and the initiation of a syn- to post-collision regime for the Altai orogen are probably at the Early Permian.
期刊介绍:
Journal of Asian Earth Sciences has an open access mirror journal Journal of Asian Earth Sciences: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review.
The Journal of Asian Earth Sciences is an international interdisciplinary journal devoted to all aspects of research related to the solid Earth Sciences of Asia. The Journal publishes high quality, peer-reviewed scientific papers on the regional geology, tectonics, geochemistry and geophysics of Asia. It will be devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be included. Papers must have international appeal and should present work of more than local significance.
The scope includes deep processes of the Asian continent and its adjacent oceans; seismology and earthquakes; orogeny, magmatism, metamorphism and volcanism; growth, deformation and destruction of the Asian crust; crust-mantle interaction; evolution of life (early life, biostratigraphy, biogeography and mass-extinction); fluids, fluxes and reservoirs of mineral and energy resources; surface processes (weathering, erosion, transport and deposition of sediments) and resulting geomorphology; and the response of the Earth to global climate change as viewed within the Asian continent and surrounding oceans.