气候变化领域集成服务门户(CCPortal): Early Cretaceous wedge extrusion in the Indo-Burma Range accretionary complex: implications for the Mesozoic subduction of Neotethys in SE Asia

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DOI	10.1007/s00531-017-1468-7
	Early Cretaceous wedge extrusion in the Indo-Burma Range accretionary complex: implications for the Mesozoic subduction of Neotethys in SE Asia
	Zhang, Ji'en; Xiao, Wenjiao; Windley, Brian F.; Cai, Fulong; Sein, Kyaing; Naing, Soe
通讯作者	Zhang, JE (通讯作者)
发表日期	2017
ISSN	1437-3254
EISSN	1437-3262
起始页码	1391
结束页码	1408
卷号	106 期号:4
英文摘要	The Indo-Burma Range (IBR) of Myanmar, the eastern extension of the Yarlung-Tsangpo Neotethyan belt of Tibet in China, contains m,langes with serpentinite, greenschist facies basalt, chert, sericite schist, silty slate and unmetamorphosed Triassic sandstone, mudstone and siltstone interbedded with chert in the east, and farther north high-pressure blueschist and eclogite blocks in the Naga Hills m,lange. Our detailed mapping of the Mindat and Magwe sections in the middle IBR revealed a major similar to 18 km antiformal isocline in a m,lange in which greenschist facies rocks in the core decrease in grade eastwards and westwards symmetrically 'outwards' to lower grade sericite schist and silty slate, and at the margins to unmetamorphosed sediments, and these metamorphic rocks are structurally repeated in small-scale imbricated thrust stacks. In the Mindat section the lower western boundary of the isoclinal m,lange is a thrust on which the metamorphic rocks have been transported over unmetamorphosed sediments of the Triassic Pane Chaung Group, and the upper eastern boundary is a normal fault. These relations demonstrate that the IBR metamorphic rocks were exhumed by wedge extrusion in a subduction-generated accretionary complex. Along strike to the north in the Naga Hills is a comparable isoclinal m,lange in which central eclogite lenses are succeeded 'outwards' by layers of glaucophane schist and glaucophanite, and to lower grade greenschist facies sericite schist and slate towards the margins. In the Natchaung area (from west to east) unmetamorphosed Triassic sediments overlie quartzites, sericite schists, actinolite schists and meta-volcanic amphibolites derived from MORB-type basalt, which are in fault contact with peridotite. Olivine in the peridotite has undulatory extinction suggesting deformation at 600-700 A degrees C, similar to the peak temperature of the amphibolite; these relations suggest generation in a metamorphic sole. The amphibolites have U/Pb zircon ages of 119 +/- 3 Ma and 115 Ma, which are close to the zircon ages of nearby calc-alkaline granite and diorite, which belong to an active continental margin arc that extends along the western side of the Shan-Thai block. The IBR accretionary complex and the active continental margin arc were generated during Early Cretaceous (115-128 Ma) subduction of the Neotethys Ocean.
关键词	MANIPUR OPHIOLITE COMPLEX MYANMAR OROGENIC BELT ZIRCON U-PB NORTHEAST INDIA NAGA HILLS TECTONIC EVOLUTION WESTERN MYANMAR EMPLACEMENT HISTORY PLATE STRATIGRAPHY SOUTHEAST-ASIA
英文关键词	Myanmar; Indo-Burma Range; Accretionary complex; Wedge extrusion; Early Cretaceous; Neotethys
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000401629200013
来源期刊	INTERNATIONAL JOURNAL OF 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/259055
推荐引用方式 GB/T 7714	Zhang, Ji'en,Xiao, Wenjiao,Windley, Brian F.,et al. Early Cretaceous wedge extrusion in the Indo-Burma Range accretionary complex: implications for the Mesozoic subduction of Neotethys in SE Asia[J]. 中国科学院青藏高原研究所,2017,106(4).
APA	Zhang, Ji'en,Xiao, Wenjiao,Windley, Brian F.,Cai, Fulong,Sein, Kyaing,&Naing, Soe.(2017).Early Cretaceous wedge extrusion in the Indo-Burma Range accretionary complex: implications for the Mesozoic subduction of Neotethys in SE Asia.INTERNATIONAL JOURNAL OF EARTH SCIENCES,106(4).
MLA	Zhang, Ji'en,et al."Early Cretaceous wedge extrusion in the Indo-Burma Range accretionary complex: implications for the Mesozoic subduction of Neotethys in SE Asia".INTERNATIONAL JOURNAL OF EARTH SCIENCES 106.4(2017).