气候变化领域集成服务门户(CCPortal): Early Cretaceous bimodal volcanic rocks in the Yinshan belt; North China Craton: age; petrogenesis; and geological significance

CCPortal

DOI	10.1007/s00531-020-01895-9
	Early Cretaceous bimodal volcanic rocks in the Yinshan belt; North China Craton: age; petrogenesis; and geological significance
	Chang Z.; Dong G.; Mo X.; Dong P.; Li H.
发表日期	2020
ISSN	14373254
起始页码	2189
结束页码	2207
卷号	109 期号:6
英文摘要	Determining the age and petrogenesis of the Mesozoic magmatic rocks may provide crucial evidence regarding the tectonic setting and evolution of the North China Craton (NCC). In this paper, we present new zircon U–Pb ages and geochemical data for bimodal volcanic rocks from Zhuozi area in the eastern Yinshan belt, NCC, to discuss their petrogenesis and tectonic implications. The volcanic rock suite consists of basalts, rhyolites, and trachytes. According to the results of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), the rhyolitic and trachytic rocks have zircon U–Pb ages of 136.9 ± 0.8 Ma and 134.0 ± 1.7 Ma, respectively, representing their eruption ages. The basalts are enriched in large-ion lithophile elements (LILE; Ba, Rb, Sr, and Th) and light rare-earth elements (LREE), and are relatively depleted in high field strength elements (HFSE; Nb, Ta, and Ti). In addition, the basalts are characterized by high fractionations of rare-earth elements (REE), with (La/Yb)N = 24.87–42.85. These features suggest that they were derived from low-degree partial melting of enriched lithospheric mantle metasomatized by subduction-related components. The rhyolitic rocks have low mean Al2O3 (12.26 wt%) and TiO2 (0.14 wt%) contents and Mg# (14.92) values, with relatively low total REE abundances. They have high alkali and Zr, Ce, Y, and Nb contents and high Ga/Al ratios, with notably positive Pb and negative Sr, Ba, and Eu anomalies observed in the primitive mantle-normalized trace element diagram. These features indicate that the rocks exhibit characteristics of A1-type granite and likely derived from the partial melting of a crustal source. The trachytic rocks are show moderate trace elements and SiO2, MgO, Fe2O3T, and TiO2 contents. They were possibly generated by fractional crystallization of the underplating basaltic magmas and assimilated minor crustal materials. The geochemical characteristics, in combination with the regional geology, suggest that the bimodal volcanic rocks formed in an intraplate extensional setting likely associated with the retreat of the subducted Paleo-Pacific plate. © 2020, Geologische Vereinigung e.V. (GV).
英文关键词	Bimodal volcanic rocks; North China Craton; Petrogenesis; Yinshan belt
语种	英语
scopus关键词	age determination; bimodal association; Cretaceous; petrogenesis; regional geology; tectonic setting; uranium-lead dating; volcanic rock; China; North China Block; Lile; Trachytes
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147637
作者单位	School of Earth Science and Resources, China University of Geosciences Beijing, 29 Xueyuan Road, Beijing, 100083, China
推荐引用方式 GB/T 7714	Chang Z.,Dong G.,Mo X.,et al. Early Cretaceous bimodal volcanic rocks in the Yinshan belt; North China Craton: age; petrogenesis; and geological significance[J],2020,109(6).
APA	Chang Z.,Dong G.,Mo X.,Dong P.,&Li H..(2020).Early Cretaceous bimodal volcanic rocks in the Yinshan belt; North China Craton: age; petrogenesis; and geological significance.International Journal of Earth Sciences,109(6).
MLA	Chang Z.,et al."Early Cretaceous bimodal volcanic rocks in the Yinshan belt; North China Craton: age; petrogenesis; and geological significance".International Journal of Earth Sciences 109.6(2020).