The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese

doi:10.1016/j.lithos.2018.03.009

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	The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese
	Jiang, Jun-Sheng 1; Zheng, You-Ye 1,2; Gao, Shun-Bao 1; Zhang, Yong-Chao 1; Huang, Jian 4; Liu, Jun 1; Wu, Song 2; Xu, Jing 3; Huang, Liang-Liang 3
刊名	LITHOS
	2018-05-01
卷号	308 页码:294-315
关键词	Linzizong volcanic rocks Granite porphyry Nuocang Western Gangdese belt Tibet
ISSN号	0024-4937
DOI	10.1016/j.lithos.2018.03.009
英文摘要	The newly discovered polymetallic Nuocang Pb-Zn skarn deposit is located in the southern Lhasa subterrane, western Gangdese, Tibet. The orebodies occur primarily at the contact zone between the Angjie Formation and the Linzizong volcanic rocks of Dianzhong Formation (LDF) that are dominated by basaltic andesitic tuff and rhyolite. Zircon U-Pb dating for two granite porphyries yield ages of 72.4 +/- 0.2 Ma and 73.4 +/- 0.9 Ma, which are different from the ages (similar to 69-60 Ma) of the LDF in the eastern Gangdese. The basaltic andesite tuff at Nuocang exhibits enrichment of MgO, TiO2, LILE, and LREE, with a relative depletion of SiO2, K2O, HFSE, and HREE, low Sr/Y ratios (32.9-38.0), and weak negative Eu anomalies (mean 0.86). They have Sr-87/Sr-86((i)) from 0.70695 to 0.70807 and epsilon(Nd(t)) values between -4.3 and -5.9.These features are similar to the Linzizong volcanic rocks of Dianzhong Formation in the Linzhou basin, indicating that they were associated with partial melting of mantle wedge mixing with 25-35% ancient Lhasa terrane basement. The rhyolite and granite porphyry show high SiO2 and K2O, and low Sr/Y ratio (1.2-9.9), enrichment of LILE and LREE and strong depletion of the HFSEs. They have pronounced negative Eu anomalies (mean 0.46), and epsilon(Hf (t)) values of the granite porphyry zircons range from -22.0 to -6.0. All these features suggest that they are the product of anatexis of ancient crustal materials heated by mantle-derived magma, the latter derived from Neo-Tethyan slab dehydration mechanisms. Combined with the previous geochronological and geochemical data, we proposed that the Nuocang district of western Gangdese in the southern Lhasa subterrane contains an ancient block, and the igneous rocks here were triggered by the Neo-Tethyan slab rollback starting at similar to 82 Ma. The western Gangdese contains more ancient continental crustal materials and Late Cretaceous-Eocene Linzizong volcanic rocks and coeval intrusions than in the eastern Gangdese. Thus the western Gangdese block displays greater potential for deposits associated with Late Cretaceous-Eocene magmatism including porphyry Mo, polymetallic skarn (W-Sn-Mo-Pb-Zn-Ag), base and precious metal epithermal (Pb-Zn-Ag-Au), cryptoexplosive breccia (Pb-Zn-Ag), and hydrothermal vein PbZn-Ag deposits. (C) 2018 Elsevier B.V. All rights reserved.
资助项目	National Key Research and Development Program of China[2016YFC0600300] ; Commonwealth Project from the Ministry of Land and Resources[201511015] ; China Geological Survey[DD20160027-2]
WOS关键词	LINZIZONG VOLCANIC SUCCESSIONS ; SOUTHERN TIBET IMPLICATIONS ; MIDOCEAN RIDGE SUBDUCTION ; PORPHYRY CU-MO ; U-PB ; LHASA TERRANE ; CONTINENTAL-CRUST ; METALLOGENIC BELT ; TRACE-ELEMENT ; GEOCHEMICAL CHARACTERISTICS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000446791000019
资助机构	National Key Research and Development Program of China ; National Key Research and Development Program of China ; Commonwealth Project from the Ministry of Land and Resources ; Commonwealth Project from the Ministry of Land and Resources ; China Geological Survey ; China Geological Survey ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; Commonwealth Project from the Ministry of Land and Resources ; Commonwealth Project from the Ministry of Land and Resources ; China Geological Survey ; China Geological Survey ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; Commonwealth Project from the Ministry of Land and Resources ; Commonwealth Project from the Ministry of Land and Resources ; China Geological Survey ; China Geological Survey ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; Commonwealth Project from the Ministry of Land and Resources ; Commonwealth Project from the Ministry of Land and Resources ; China Geological Survey ; China Geological Survey
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/89184]
专题	地质与地球物理研究所_其他部门
通讯作者	Zheng, You-Ye
作者单位	1.China Univ Geosci, Fac Earth Resources, Inst Geol Survey, Wuhan 430074, Hubei, Peoples R China 2.China Univ Geosci, Sch Earth Sci & Resources, State Key Lab Geol Proc & Resources, Beijing 100083, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, POB 9825, Beijing 100029, Peoples R China 4.East China Met Inst Geol & Explorat, Hefei 230088, Anhui, Peoples R China
推荐引用方式 GB/T 7714	Jiang, Jun-Sheng,Zheng, You-Ye,Gao, Shun-Bao,et al. The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese[J]. LITHOS,2018,308:294-315.
APA	Jiang, Jun-Sheng.,Zheng, You-Ye.,Gao, Shun-Bao.,Zhang, Yong-Chao.,Huang, Jian.,...&Huang, Liang-Liang.(2018).The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese.LITHOS,308,294-315.
MLA	Jiang, Jun-Sheng,et al."The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese".LITHOS 308(2018):294-315.