Petrogenesis and Geological Significance of the Quartz Monzonites in the Jinling Area, Western Shandong Province

Minerals

Ming Ma¹  Ya-Dong Li¹  Ji-Lei Gao¹  Zhao-Lu Zhang²  Ye Li²  Chao Zhang²  Lu-Yuan Wang² 

[1] Shandong Engineering Laboratory for High—Grade Iron Ore Exploration and Exploitation, Jinan 250100, China;The School of Resources and Environmental Engineering, Shandong University of Technology, Zibo 255049, China;

关键词: zircon U-Pb geochronology;    zircon Hf isotope;    Sr-Nd-Pb isotopes;    Western Shandong province;    North China Craton;   

DOI  :  10.3390/min12060771

来源: DOAJ

【 摘 要 】

Jinling complex pluton is a key part of the Mesozoic magmatic belt in the eastern North China Craton. However, its petrogenesis is still being debated. The Jinling complex, mainly composed of biotite diorites, hornblende diorite, augite diorites, (quartz) monzonites, and quartz diorites, is outcropped in Huashan and Heitieshan. This paper studies the zircon geochronology, zircon Hf isotope, and Sr-Nd-Pb isotope of quartz monzonites. The samples have high contents of Cr, Ni, V, Al₂O₃, Ba, Sr, and are enriched in LREEs, LILEs (K, Ba, Sr), depleted in HREEs, and HFSEs (Nb, Ta, Ti). The samples with captured zircons of ~2.5 Ga yield a weighted mean age of ~127 Ma, and the zircons have negative values of ε_Hf(t) from −3.2 to −9.4 while the ratios of ²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, ²⁰⁶Pb/²⁰⁴Pb 37.75~38.15, 15.41~15.43, 17.59~17.98, respectively. The ratios of Th/U are from 3.77 to 3.82, while the values of μ and ω are 9.18 and from 35.72 to 36.15. Meanwhile, the ratios of ⁸⁷Sr/⁸⁶Sr are higher than the ones of the mantle. Geochemical and isotopic features indicate that the quartz monzonites derived from the subcontinental lithospheric mantle that probably assimilated ancient NCC upper crust materials (~15–20%) during the magma ascent in a lithospheric extension setting.

【 授权许可】

Unknown