Petrogenesis and Tectonic Setting of the Early and Middle Jurassic Granitoids in the Chaihe Area, Central Great Xing’an Range, NE China

• Published in: Minerals (Basel) Vol. 13; no. 7; p. 917
• Main Authors: Shi, Lu, Ju, Nan, Feng, Yuhui, Zheng, Changqing, Wu, Yue, Liu, Xin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.07.2023
• Subjects: Ablation; Basalt; central Great Xing’an Range; Dehydration; Early and Middle Jurassic; Earth; Geology; Granite; granitoids; Jurassic; Lasers; Lava; Magma; Mantle; Mass spectrometry; Mineral resources; Ocean floor; Oceanic crust; Petrogenesis; Plates (tectonics); Quartz; Rocks; Scientific imaging; Sediments; Sediments (Geology); Slabs; southward subduction of the Mongol-Okhotsk oceanic plate; Subduction; Subduction (geology); Tectonics; Tectonics (Geology); Trace elements; United Kingdom; China; Russia
• ISSN: 2075-163X; 2075-163X
• DOI: 10.3390/min13070917

To ascertain the Early-to-Middle Jurassic tectonic setting in the central Great Xing’an Range, this study investigated the Early and Middle Jurassic granitoids exposed in the Chaihe area in the central Great Xing’an Range based on isotopic chronology and petrogeochemistry. The results of this study show that the Early and Middle Jurassic granitoids have emplacement ages of 179–172 Ma. Moreover, the Early and Middle Jurassic granitoids are high-K calc-alkaline unfractionated I-type granitoids and high-K calc-alkaline fractionated I-type granitoids, respectively. The magma sources of the Early and Middle Jurassic granitoids both originated from the partial melting of newly accreted lower crustal basaltic rocks. Meanwhile, the Middle Jurassic magma sources were mixed with mantle-derived materials or ocean-floor sediments formed by the dehydration and metasomatism of subducted slabs. The Early and Middle Jurassic granitoids in the study area were formed in the subduction environment of the oceanic crust, in which the Mongol-Okhotsk oceanic plate was subducted southward beneath the Eerguna and Xing’an blocks. Moreover, the Siberian plate began to collide and converge with northeast China during the Middle Jurassic.