Petrogenesis of the Ulungur Intrusive Complex, NW China, and Implications for Crustal Generation and Reworking in Accretionary Orogens

doi:10.1093/petrology/egaa018

GIG OpenIR

	Tang, Gong-Jian 1,2; Wang, Qiang 1,2,3; Wyman, Derek A.4; Dan, Wei 1,2; Ma, Lin 1; Zhang, Hai-Xiang 1; Zhao, Zhen-Hua 5
	Petrogenesis of the Ulungur Intrusive Complex, NW China, and Implications for Crustal Generation and Reworking in Accretionary Orogens
刊名	JOURNAL OF PETROLOGY
ISSN号	0022-3530
	2020-02-01
卷号	61 期号:2 页码:30
DOI	10.1093/petrology/egaa018
语种	英语
WOS研究方向	Geochemistry & Geophysics
摘要	Accretionary orogens are characterized by voluminous juvenile components (recently derived from the mantle) and knowing the origin(s) of such components is vital for understanding crustal generation. Here we present field and petrological observations, along with mineral chemistry, zircon U-Pb age and Hf-O isotope data, and whole rock geochemical and Sr-Nd isotopic data for the c.320 Ma Ulungur intrusive complex from the Central Asian Orogenic Belt. The complex consists of two different magmatic series: one is characterized by medium- to high-K calc-alkaline gabbro to monzogranite; the other is defined by peralkaline aegirine-arfvedsonite granitoids. The calc-alkaline and peralkaline series granitoids have similar depleted mantle-like Sr-Nd-Hf isotopic compositions, but they have different zircon delta O-18 values: the calc-alkaline series have mantle-like delta O-18 values with mean compositions ranging from 5.2 +/- 0.5 parts per thousand to 6.0 +/- 0.9 parts per thousand (2SD), and the peralkaline granitoids have low delta O-18 values ranging from 3.3 +/- 0.5 parts per thousand to 3.9 +/- 0.4 parts per thousand (2SD). The calc-alkaline series were derived from a hydrous sub-arc mantle wedge, based on the isotope and geochemical compositions, under garnet peridotite facies conditions. This study suggests that the magmas underwent substantial differentiation, ranging from high pressure crystallization of ultramafic cumulates in the lower crust to lower pressure crystallization dominated by amphibole, plagioclase and minor biotite in the upper crust. The peralkaline series rocks are characterized by delta O-18 values lower than the mantle and enrichment of high field strength elements (HFSEs) and heavy rare earth elements (HREEs). They likely originated from melting of preexisting hydrothermally altered residual oceanic crust in the lower crust of the Junggar intra-oceanic arc. Early crystallization of clinopyroxene and amphibole was inhibited owing to their low melting temperature, leading to HFSEs and HREEs enrichment in residual peralkaline melts during crystallization of a feldspar-dominated mineral assemblage. Thus, the calc-alkaline and peralkaline series represent episodes of crust generation and reworking, respectively, demonstrating that the juvenile isotopic signature in accretionary orogens can be derived from diverse source rocks. Our results show that reworking of residual oceanic crust also plays an important role in continental crust formation for accretionary orogens, which has not previously been widely recognized.
关键词	Central Asian Orogenic Belt crust generation crust reworking granitoid magmatic processes mineral chemistry zircon HF-O isotopes
WOS记录号	WOS:000593094800007
收录类别	SCI
引用统计
文献类型	期刊论文
条目标识符	http://ir.gig.ac.cn/handle/344008/61105
通讯作者	Tang, Gong-Jian
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Univ Sydney, Sch Geosci, Sydney, NSW 2006, Australia 5.Chinese Acad Sci, Guangzhou Inst Geochem, Key Lab Mineral & Metallogeny, Guangzhou 510640, Peoples R China
推荐引用方式 GB/T 7714	Tang, Gong-Jian,Wang, Qiang,Wyman, Derek A.,et al. Petrogenesis of the Ulungur Intrusive Complex, NW China, and Implications for Crustal Generation and Reworking in Accretionary Orogens[J]. JOURNAL OF PETROLOGY,2020,61(2):30.
APA	Tang, Gong-Jian.,Wang, Qiang.,Wyman, Derek A..,Dan, Wei.,Ma, Lin.,...&Zhao, Zhen-Hua.(2020).Petrogenesis of the Ulungur Intrusive Complex, NW China, and Implications for Crustal Generation and Reworking in Accretionary Orogens.JOURNAL OF PETROLOGY,61(2),30.
MLA	Tang, Gong-Jian,et al."Petrogenesis of the Ulungur Intrusive Complex, NW China, and Implications for Crustal Generation and Reworking in Accretionary Orogens".JOURNAL OF PETROLOGY 61.2(2020):30.