气候变化领域集成服务门户(CCPortal): Early Cretaceous subduction-modified lithosphere beneath the eastern Qinling Orogen revealed from the Daying volcanic sequence in central China

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DOI	10.1016/j.jseaes.2019.02.013
	Early Cretaceous subduction-modified lithosphere beneath the eastern Qinling Orogen revealed from the Daying volcanic sequence in central China
	Zhang, Feifei; Wang, Yuejun; Dong, Yunpeng; Cawood, Peter A.; Fan, Weiming
通讯作者	Zhang, FF (通讯作者)
发表日期	2019
ISSN	1367-9120
EISSN	1878-5786
起始页码	209
结束页码	228
卷号	176
英文摘要	New geochronological, geochemical and Sr-Nd-Hf isotopic data for the early Cretaceous Daying volcanic sequence, eastern Qinling Orogen, provides a probe into the nature of, and tectonic process operating in, the underlying Mesozoic mantle. The volcanic rocks in the sequence are composed of basaltic trachyandesite, pyroxene-andesite, trachyandesite and trachyte. They yield zircon U-Pb and whole-rock Ar-40/Ar-39 plateau ages of 134-124 Ma, roughly synchronous with the Cretaceous igneous rocks throughout the eastern Qinling and Dabie orogens. Clinopyroxene and plagioclase phenocrysts of the volcanic rocks exhibit simple normal zonation with higher mg-number and An content in the core relative to the rim. The amphibole is characterized by tschermakite and tschermakitic hornblende with mg-number of 50-67. The Daying volcanic rocks have variable SiO2 (54.27-63.44 wt%), Al2O3 (15.39-20.34 wt%), FeOt (5.23-9.94 wt%), and MgO (1.05-4.03 wt%) contents with low mg-number (26-49). They exhibit arc-like REE-and PM-normalized patterns with significant negative Nb-Ta anomalies, and highly-enriched Sr-Nd isotopic composition with (Sr-87/Sr-86)(t) ratios of 0.7066-0.7078 and ENd(t) values of -15.5 similar to -11.0. Their zircons exhibit strongly negative Ew(t) values ranging from -27.3 to -17.2 and two-staged model ages from 2.90 Ga to 2.28 Ga. Such geochemical signatures suggest that the Daying volcanic rocks were derived from a hybridized source of the North China Craton enriched mantle with the input of some Yangtze crustal materials created by Triassic deep-subduction digestion. They also share similar eruption time, as well as elemental and Sr-Nd-Hf isotopic compositions, with those in the southern margin of the North China Craton, suggesting a northward subduction of the Yangtze block. It is proposed that the volcanic rocks are petrogenetically related to an early Cretaceous extensional event along the Qinling-Dabie Orogenic belt in response to unroofing of the thickened lithosphere.
关键词	ZIRCON U-PB CRUST-MANTLE INTERACTION PRESSURE METAMORPHIC ROCKS HF ISOTOPE GEOCHEMISTRY NORTH-CHINA CONTINENTAL-CRUST TRACE-ELEMENT DABIE OROGEN LU-HF MESOZOIC GRANITOIDS
英文关键词	Geochronology; Sr-Nd-Hf isotopic compositions; Early Cretaceous volcanics; Subduction-modified mantle source; Eastern Qinling Orogen
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000466823600017
来源期刊	JOURNAL OF ASIAN EARTH SCIENCES
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259523
推荐引用方式 GB/T 7714	Zhang, Feifei,Wang, Yuejun,Dong, Yunpeng,et al. Early Cretaceous subduction-modified lithosphere beneath the eastern Qinling Orogen revealed from the Daying volcanic sequence in central China[J]. 中国科学院青藏高原研究所,2019,176.
APA	Zhang, Feifei,Wang, Yuejun,Dong, Yunpeng,Cawood, Peter A.,&Fan, Weiming.(2019).Early Cretaceous subduction-modified lithosphere beneath the eastern Qinling Orogen revealed from the Daying volcanic sequence in central China.JOURNAL OF ASIAN EARTH SCIENCES,176.
MLA	Zhang, Feifei,et al."Early Cretaceous subduction-modified lithosphere beneath the eastern Qinling Orogen revealed from the Daying volcanic sequence in central China".JOURNAL OF ASIAN EARTH SCIENCES 176(2019).