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Geoscience ›› 2022, Vol. 36 ›› Issue (04): 1155-1172.DOI: 10.19657/j.geoscience.1000-8527.2022.04.18

• Geochemistry and Water Resources • Previous Articles     Next Articles

Genesis and Geological Significance of Late Archean Syeno-monzogranite in Western Shandong Province

YANG Fan(), CHEN Yuelong(), YU Yang   

  1. School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China
  • Received:2021-09-22 Revised:2021-10-22 Online:2022-08-10 Published:2022-09-09
  • Contact: CHEN Yuelong

Abstract:

The Western Shandong is located in the east of North China Craton, which is an important area to study the Archean evolution.Petrology, geochemistry and zircon U-Pb dating and Hf isotopic composition were studied on the syeno-monzogranite in the southwest of Western Shandong Province.The syeno-monzogranite is characterized by calc-alkaline and peraluminous affinities.Zircon U-Pb dating shows that the syeno-monzogra-nite emplaced at~2 540 Ma to~2 530 Ma.Zircon Hf isotopic compositions show that they were primarily molten by TTG rocks of~2.70 Ga, and there is recycled ancient crustal component. The mixing calculation results under constraints of isotopic and trace element compositions confirm that the primary magma of syeno-monzogranite is composed of the mixing of 97% of the juvenile TTG crustal material after partial melting and 3% of metamorphic supracrustal rocks after partial melting.Combined with previous studies, we propose that the syeno-monzogranite was formed in an extensional tectonic environment.The late Neoarchean magmatism in Western Shandong was related to slab rollback.The upwelling of asthenosphere caused by the rollback provided heat source for the formation of this group of rocks.

Key words: North China Craton, syeno-monzogranite, late Neoarchean, rollback, Western Shandong

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