Ascertainment and environment of the OIB-type basalts from the Dongbo;ophiolite in the western part of Yarlung Zangbo Suture Zone

	Ascertainment and environment of the OIB-type basalts from the Dongbo;ophiolite in the western part of Yarlung Zangbo Suture Zone
	Liu Fei 1; Yang JingSui ; Chen SongYong ; Liang FengHua ; Niu XiaoLu ; Li ZhaoLi ; Lian DongYang 2
刊名	ACTA PETROLOGICA SINICA
	2013
卷号	29 期号:6 页码:1909-1932
关键词	OIB-type basalt Chert Plume hotspot Ophiolite Yarlung Zangbo Suture Zone Tibet
ISSN号	1000-0569
英文摘要	The western part of the Yarlung Zangbo Suture Zone (YZSZ) is divided into two sub-belts; the genesis of the south plays a crucial role in the interpretation a the geological setting, magmatic and tectonic processes of the Neo-Tethyan Ocean. Previous research about the Dongbo ophiolite was poor, due to harsh natural environment and traffic inconvenience. This paper reports the data on petrography and geochemistry of OIB-type basalts and associated sedimentary rocks in the Dongbo ophiolite and discusses their source characteristics and geological significance. Dongbo ophiolite consists of peridotite (including harzburgite, minor Cpx enriched harzburgite and dunite), mafic dikes and submarine volcanic-sendimentary rock sequences, no typical cumulates and pillow lavas. The stable marine volcanic-sedimentary sequences mainly composed of siliceous limestone, red chert, shale interbedded sandstone, basalt and basaltic volcaniclastic rocks. OIB-type basalts are characterized by low SiO2 and MgO, high TiO2, P2O5 and (K2O + Na2O) content, enrichment of Nb, Ta and REE, depletion of Th, K, Pb, Sr. Trace elements and Sr, Nd, Pb isotope data show that these basaltic lavas were derived from 2% to 5% partial melting of garnet spinel lherzolite. Siliceous rocks are of biogenic origin, and show a close relation to terrigenous component and seamount or island arc basalts. Above evidences indicate that the Dongbo volcano-sedimentary sequences have the typical seamount features, and the Dongbo ophiolite probably is related to a plume hotspot. Therefore, it can be considered, the plume hotspot underplating and interacting with the subcontinental lithospheric mantle of the Gondwana northern margin not only promoted opening the Daba-Xiugugabu Tethyan oceanic basin, but also prompted diamonds and other abnormal mantle minerals to be migrated upper mantle and wrapped in peridotite and chromite.
学科主题	火成岩岩石学
WOS关键词	LARGE IGNEOUS PROVINCE ; TETHYAN UPPER-MANTLE ; SOUTHERN TIBET ; LUOBUSA ; OPHIOLITE ; XIGAZE OPHIOLITE ; RARE-EARTH ; OCEANIC-CRUST ; GEOCHEMICAL ; CHARACTERISTICS ; GEOLOGICAL SIGNIFICANCE ; SEQUENCE STRATIGRAPHY
WOS研究方向	Geology
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000322427000005
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40157]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, State Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China. 2.E China Inst Technol, State Key Lab Breeding Base Nucl Resources & Envi, Nanchang 330013, Peoples R China. 3.China Univ Geosci, Fac Earth Sci, Wuhan 430074, Peoples R China.
推荐引用方式 GB/T 7714	Liu Fei,Yang JingSui,Chen SongYong,et al. Ascertainment and environment of the OIB-type basalts from the Dongbo;ophiolite in the western part of Yarlung Zangbo Suture Zone[J]. ACTA PETROLOGICA SINICA,2013,29(6):1909-1932.
APA	Liu Fei.,Yang JingSui.,Chen SongYong.,Liang FengHua.,Niu XiaoLu.,...&Lian DongYang.(2013).Ascertainment and environment of the OIB-type basalts from the Dongbo;ophiolite in the western part of Yarlung Zangbo Suture Zone.ACTA PETROLOGICA SINICA,29(6),1909-1932.
MLA	Liu Fei,et al."Ascertainment and environment of the OIB-type basalts from the Dongbo;ophiolite in the western part of Yarlung Zangbo Suture Zone".ACTA PETROLOGICA SINICA 29.6(2013):1909-1932.