气候变化领域集成服务门户(CCPortal): Petrogenesis and Geodynamic Implications of Cretaceous Nb-Enriched Mafic Dykes in the East Kunlun Orogen, Northern Tibet Plateau: Constraints from Geochronology, Geochemistry and Sr-Nd Isotopes

CCPortal

DOI	10.3390/min14010089
	Petrogenesis and Geodynamic Implications of Cretaceous Nb-Enriched Mafic Dykes in the East Kunlun Orogen, Northern Tibet Plateau: Constraints from Geochronology, Geochemistry and Sr-Nd Isotopes
	Chu, Zhiqiang; Zhou, Hu; Wang, Mingchi; Zhou, Jiaming; Xiong, Fuhao
发表日期	2024
EISSN	2075-163X
卷号	14 期号:1
英文摘要	There is a magmatic lull period in the East Kunlun orogen (EKO) during the Jurassic to the Cretaceous. However, due to the lack of records of magmatic activity restricts our understanding of the late Mesozoic magmatic-tectonic evolution of the EKO. Herein, an integrated study of geochronology, whole-rock geochemistry and Sr-Nd isotopes were conducted for the Cretaceous mafic dykes in the EKO, Northern Tibet Plateau, to reveal their petrogenesis and geodynamic implications. LA-ICP-MS Zircon U-Pb dating reveals that the studied mafic dykes comprising diabase and diabase porphyry emplaced at ca. 80.9 +/- 0.8 Ma. The Cretaceous mafic dykes have low contents of SiO2 (46.36 wt.%similar to 47.40 wt.%) but high contents of MgO (6.79 wt.%similar to 7.38 wt.%), TiO2 (1.91 wt.%similar to 2.13 wt.%), Nb (12.4 similar to 18.3 ppm) and Nb/U ratio (31 similar to 39), resembling Nb-enriched mafic dykes. They exhibit chondrite-normalized rare earth element (REE) and primitive mantle-normalized trace element patterns, remarkably similar but not identical to the oceanic island basalts (OIB). The moderate REE fractionation ((La/Yb)(N) = 3.55 similar to 5.37), weak negative Eu anomalies (delta Eu = 0.87 similar to 0.97) and relative enrichment of Rb, Ba, K, as well as high contents of Cr and Ni and slightly depleted Sr-Nd isotopes (epsilon Nd(t) = -0.18 similar to 1.33), suggest that the studied dykes originate from a partial melting of spinel lherzolite and a little of garnet which was previously modified by subducted sediments. Combined with other evidence, we propose that the studied Cretaceous Nb-enriched mafic dykes in the Northern Tibet Plateau were formed in the intraplate setting, which may be a partial melting of the enriched mantle in the lower lithosphere caused by the activity of the East Kunlun strike-slip fault.
关键词	East Kunlun orogen Cretaceous Nb-enriched mafic dykes Sr-Nd isotopes
英文关键词	CONTINENTAL-CRUST; INTRAPLATE MAGMATISM; TRACE-ELEMENTS; WESTERN CHINA; SUBDUCTION; MANTLE; ARC; VOLCANISM; EVOLUTION; BASALTS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy ; Mining & Mineral Processing
WOS记录号	WOS:001152405800001
来源期刊	MINERALS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283274
作者单位	Chengdu University of Technology; Chengdu University of Technology
推荐引用方式 GB/T 7714	Chu, Zhiqiang,Zhou, Hu,Wang, Mingchi,et al. Petrogenesis and Geodynamic Implications of Cretaceous Nb-Enriched Mafic Dykes in the East Kunlun Orogen, Northern Tibet Plateau: Constraints from Geochronology, Geochemistry and Sr-Nd Isotopes[J],2024,14(1).
APA	Chu, Zhiqiang,Zhou, Hu,Wang, Mingchi,Zhou, Jiaming,&Xiong, Fuhao.(2024).Petrogenesis and Geodynamic Implications of Cretaceous Nb-Enriched Mafic Dykes in the East Kunlun Orogen, Northern Tibet Plateau: Constraints from Geochronology, Geochemistry and Sr-Nd Isotopes.MINERALS,14(1).
MLA	Chu, Zhiqiang,et al."Petrogenesis and Geodynamic Implications of Cretaceous Nb-Enriched Mafic Dykes in the East Kunlun Orogen, Northern Tibet Plateau: Constraints from Geochronology, Geochemistry and Sr-Nd Isotopes".MINERALS 14.1(2024).