Postcollisional delamination and partial melting of enriched lithospheric mantle: Evidence from Oligocene (ca. 30 Ma) potassium-rich lavas in the Gemuchaka area of the central Qiangtang Block, Tibet

doi:10.1130/B31911.1

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Postcollisional delamination and partial melting of enriched lithospheric mantle: Evidence from Oligocene (ca. 30 Ma) potassium-rich lavas in the Gemuchaka area of the central Qiangtang Block, Tibet
	Ou, Quan 1,2; Wang, Qiang 1,3,4; Wyman, Derek A.5; Zhang, Chunfu 6; Hao, Lu-Lu 1; Dan, Wei 1; Jiang, Zi-Qi 1,7; Wu, Fu-Yuan 8; Yang, Jin-Hui 8; Zhang, Hai-Xiang 1
刊名	GEOLOGICAL SOCIETY OF AMERICA BULLETIN
	2019-07-01
卷号	131 期号:7-8 页码:1385-1408
ISSN号	0016-7606
DOI	10.1130/B31911.1
英文摘要	Postcollisional potassium (K)-rich magmatic rocks have important implications for unveiling the deep geodynamic processes active during the evolution of orogenic belts and the surface uplift of plateaus. However, their petrogenesis remains highly controversial. Here we report on zircon U-Pb and mineral Ar-40-Ar-39 age, zircon Hf-O isotope, mineral composition, whole-rock major and trace element composition, and Nd-Sr isotope data for the postcollisional K-rich lavas in the Gemuchaka area of the central Qiangtang Block (central Tibet). Age dating suggests that these lavas were generated in the late Early Oligocene (ca. 30 Ma). Two series of rocks were recognized: silica-undersaturated and -saturated lavas. Both series are geochemically characterized by continuous variation trends. All rocks are enriched in light rare earth elements (LREEs) relative to heavy REEs (HREEs) and depleted in Ta-Nb-Ti, with negligible Sr and Eu and obviously positive Pb anomalies. The rocks have higher Th/ La (0.2-0.8) and Nb/Ta (18.6-19.8) values than asthenospheric mantle-derived rocks but slightly variable values of epsilon(Nd) (t) (-6.0 to -4.6), (Sr-87/Sr-86)(i) (0.7076-0.7083), and zircon epsilon(HF)(t) (-7.2 to +0.8) and delta O-18 (7.1-8.5 parts per thousand). We suggest that the parental magmas of these K-rich lavas were likely derived by variable partial melting of lithospheric mantle metaso-matized by subducting continental sediment-derived melts with the addition of minor asthenospheric components. Element modeling results suggest that the basic end members were likely generated by fractionation processes dominated by olivine and minor clinopyroxene from parental magmas, and some other evolved rocks were generated by crystal (olivine, clinopyroxene, Fe-Ti oxides) fractionation from basic magmas. Combining geological and Cenozoic magmatic rock data in the Qiangtang Block, we propose that the Gemuchaka magmatism was most likely triggered by the delamination of lithospheric mantle thickened by early (Paleocene- Eocene) intracontinental subduction and subsequent asthenospheric upwelling.
资助项目	National Key R and D Program of China[2016YFC0600309] ; National Key R and D Program of China[2016YFC0600407] ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences[XDA2007030402] ; Key Program of the Chinese Academy of Sciences[QYZDJ-SSW-DQC026] ; National Natural Science Foundation of China[41630208] ; Talent Project of Guangdong Province[2014TX01Z079] ; GIGCAS 135 project[135TP201601]
WOS关键词	ROMAN MAGMATIC PROVINCE ; ALKALINE VOLCANIC-ROCKS ; O ISOTOPIC COMPOSITIONS ; SONGPAN-GANZI FLYSCH ; EAST-WEST EXTENSION ; U-PB GEOCHRONOLOGY ; CONTINENTAL-CRUST ; NORTHERN TIBET ; TRACE-ELEMENT ; K-RICH
WOS研究方向	Geology
语种	英语
出版者	GEOLOGICAL SOC AMER, INC
WOS记录号	WOS:000471802800017
资助机构	National Key R and D Program of China ; National Key R and D Program of China ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Talent Project of Guangdong Province ; Talent Project of Guangdong Province ; GIGCAS 135 project ; GIGCAS 135 project ; National Key R and D Program of China ; National Key R and D Program of China ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Talent Project of Guangdong Province ; Talent Project of Guangdong Province ; GIGCAS 135 project ; GIGCAS 135 project ; National Key R and D Program of China ; National Key R and D Program of China ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Talent Project of Guangdong Province ; Talent Project of Guangdong Province ; GIGCAS 135 project ; GIGCAS 135 project ; National Key R and D Program of China ; National Key R and D Program of China ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Strategic Priority Research Program (A) of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; Key Program of the Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Talent Project of Guangdong Province ; Talent Project of Guangdong Province ; GIGCAS 135 project ; GIGCAS 135 project
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/92484]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者	Wang, Qiang
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 2.Cent S Univ, Sch Geosci & Infophys, Key Lab Metallogen Predict Nonferrous Met & Geol, Minist Educ, Changsha 410083, Hunan, Peoples R China 3.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 4.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 5.Univ Sydney, Sch Geosci, Sydney, NSW 2006, Australia 6.Ft Hays State Univ, Dept Geosci, Hays, KS 67601 USA 7.Guilin Univ Technol, Sch Earth Sci, Guilin 541004, Peoples R China 8.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Ou, Quan,Wang, Qiang,Wyman, Derek A.,et al. Postcollisional delamination and partial melting of enriched lithospheric mantle: Evidence from Oligocene (ca. 30 Ma) potassium-rich lavas in the Gemuchaka area of the central Qiangtang Block, Tibet[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2019,131(7-8):1385-1408.
APA	Ou, Quan.,Wang, Qiang.,Wyman, Derek A..,Zhang, Chunfu.,Hao, Lu-Lu.,...&Li, Jie.(2019).Postcollisional delamination and partial melting of enriched lithospheric mantle: Evidence from Oligocene (ca. 30 Ma) potassium-rich lavas in the Gemuchaka area of the central Qiangtang Block, Tibet.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,131(7-8),1385-1408.
MLA	Ou, Quan,et al."Postcollisional delamination and partial melting of enriched lithospheric mantle: Evidence from Oligocene (ca. 30 Ma) potassium-rich lavas in the Gemuchaka area of the central Qiangtang Block, Tibet".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 131.7-8(2019):1385-1408.