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Geoscience ›› 2022, Vol. 36 ›› Issue (03): 862-875.DOI: 10.19657/j.geoscience.1000-8527.2021.151

• Petrology • Previous Articles     Next Articles

LA-ICP-MS Zircon U-Pb Dating,Petrogenesis and Tectonic Setting of the Daguishan Pluton in Northwestern Guangdong

ZHANG Honghui1(), XIE Caifu2(), CHEN Kai3, YUAN Yongsheng1, YU Yangzhong1, ZHANG Liyuan4, CHEN Guiren1, LI Hong1, ZHAN Huasi5, SHI Haitao6, CAI Quanyu1, YU Yifan1   

  1. 1. Kunming Natura Resource Comprehensive Investigation Center of China Geological Survey,Kunming,Yunnan 650100, China
    2. East China University of Technology, Nanchang,Jiangxi 330000,China
    3. Hainan Wuhuajinyuan Mining Co., Ltd., Dongfang,Hainan 572633,China
    4. Geophysical Investigation Center of China Geological Survey, Langfang,Hebei 065000,China
    5. Haikou Marine Geological Investigation Center of China Geological Survey,Haikou,Hainan 571127,China
    6. Urumqi Natural Resources Comprehensive Investigation Center of China Geological Survey, Urumqi,Xinjiang 830000, China
  • Received:2021-07-07 Revised:2021-08-11 Online:2022-06-10 Published:2022-07-19
  • Contact: XIE Caifu

Abstract:

To deepen our understanding on Caledonian magmatic rock evolution in northwest Guangdong, the petrology, petrography, isotope chronology, petrogeochemistry and Sm-Nd isotope geochemistry of the Daguishan pluton in northwest Guangdong is carried out.The result shows the Daguishan pluton is located in the northwest margin of the Fogang complex pluton in Guangdong Province, and the lithology is medium-/coarse-grained biotite syenogranite.LA-ICP-MS zircon U-Pb dating shows that its age to be (445.9±3.6) Ma, belonging to the Late Ordovician intrusive rock.The Daguishan pluton is rich in Si,K, high differentiation index and low Ca, Mg and Fe. The rocks show the total amount of REE is medium to low, the fractionation degree of LREE and HREE is low with negative Eu anomaly. The monzogranite is also enriched in LILEs(e.g., Rb,Th,U,K,La,Ce and Nd) and depleted in P,Sr,Ba and Ti. (87Sr/86Sr)i value is 0.025,3-0.100,2, and εNd(t) value is -3.15--5.26 with lower TDM2 value. Based on the geochronological and geochemical characteristics of the Daguishan pluton, it is inferred that the source area is the crust material with low maturity or the mixing of a certain proportion of crust mantle material. The crust gets extended due to the collapse of orogenic belt and the upwelling of asthenosphere. Due to mantle uplift, mantle-derived mafic magmatites and potassic-basalt magmatites were formed by upwelling or underplating.

Key words: Fogang pluton, U-Pb dating, Nd isotope, granite, Late Ordovician

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