10.6084/M9.FIGSHARE.17026702.V1
Kadio Aka D. Koua
Kadio Aka D.
Koua
Huashan Sun
Huashan
Sun
Huan Li
Huan
Li
Zhanke Li
Zhanke
Li
Hui Yang
Hui
Yang
Qingming Sun
Qingming
Sun
Ohouo Rebecca Mondah
Ohouo Rebecca
Mondah
Koffi Alexis N’dri
Koffi Alexis
N’dri
Early Cretaceous mafic enclaves from the Jiaodong Peninsula of NNE China and what they reveal about lithospheric melts and granodiorite genesis: the Yashan example
<p>Mafic microgranular enclaves (MMEs) are hosted by the Early Cretaceous granitic plutons from the Jiaodong Peninsula and are crucial for constraining the petrogenesis of these plutons and understanding the lithospheric evolution in the eastern North China Craton (NCC). This paper presents new geochronological, bulk-rock geochemistry, and Sr-Nd-Hf isotope data for Yashan granodiorite and its MMEs in an effort to build an integrated model of the geodynamic setting during the Early Cretaceous. Zircon U–Pb dating indicates that Yashan granodiorite (116 ± 0.42 Ma) is coeval with its MMEs (117 ± 0.81 Ma). The MMEs display magmatic textures and disequilibrium textures such as acicular apatites, plagioclase with reverse zoning, and overgrowth of amphibole around pyroxene, indicating magma mingling/mixing. The SiO<sub>2</sub> (55.64–59.9 wt.%), MgO (3.34–5.25 wt.%), Cr (74–245 ppm), and Ni (24–91.2 ppm) contents of the Yashan MMEs combined with their Sr-Nd-Hf compositions that are identical to local arc-like mafic dikes suggest that their primary magma derived from partial melting of a metasomatised lithospheric mantle. Yashan granodiorite is characterized by relatively high SiO<sub>2</sub> (66.93–67.63 wt.%) and low MgO (1.66–1.67 wt.%) contents, I-type, high-K calc-alkaline, metaluminous affinities, and corresponding Hf model ages from Neoarchean-Paleoproterozoic, which indicate that the felsic magma was derived from partial melting of ancient NCC lower continental crust. Our data combined with previous studies on Early Cretaceous MMEs and host granites in the Jiaodong Peninsula indicate that the Cretaceous magmatism is the result of rollback of the subducting Paleo-Pacific plate beneath the eastern NCC. Asthenospheric mantle convection generated by slab rollback induced the thinning of the lithosphere and provided necessary heat to cause partial melting of the lithospheric mantle and overlying lower crust, followed by crustal-mantle interaction. The emplacement of Yashan granodiorite and other Weideshan granites and hosted MMEs indicates the peak of lithospheric thinning.</p>
Biochemistry
Physiology
Evolutionary Biology
Environmental Sciences not elsewhere classified
Chemical Sciences not elsewhere classified
Ecology
Cancer
Inorganic Chemistry
Taylor & Francis
2021
2021-11-16
2024-02-14
Journal contribution
79367 Bytes
10.6084/m9.figshare.17026702
10.1080/00206814.2021.2001384
CC BY 4.0