气候变化领域集成服务门户(CCPortal): Crustal deformation and exhumation within the India-Eurasia oblique convergence zone: New insights from the Ailao Shan-Red River shear zone

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DOI	10.1130/B35975.1
	Crustal deformation and exhumation within the India-Eurasia oblique convergence zone: New insights from the Ailao Shan-Red River shear zone
	Zhang, B.; Chen, S. Y.; Wang, Y.; Reiners, P. W.; Cai, F. L.; Speranza, E.; Zhang, J. J.; Zhong, D. L.; Liu, K.
通讯作者	Zhang, B (通讯作者)
发表日期	2022
ISSN	0016-7606
EISSN	1943-2674
起始页码	1443
结束页码	1467
卷号	134 期号:5-6
英文摘要	During the collision of India and Eurasia, regional-scale strike-slip shear zones played a key role in accommodating lateral extrusion of blocks, block rotation, and vertical exhumation of metamorphic rocks as presented by deformation on the Ailao Shan-Red River shear zone (ARSZ) in the Eastern Himalayan Syntaxis region and western Yunnan, China. We report structural, mica Ar/Ar, apatite fission-track (AFT), and apatite (UTh)/He (AHe) data from the Diancangshan massif in the middle segment of the ARSZ. These structural data reveal that the massif forms a region-scale antiform, bordered by two branches of the ARSZ along its eastern and western margins. Structural evidence for partial melting in the horizontal mylonites in the gneiss core document that the gneiss experienced a horizontal shear deformation in the middle crust. Muscovite Ar/Ar ages of 36-29 Ma from the core represent cooling ages. Muscovite Ar/Ar ages of 25 and 17 Ma from greenschist-facies mylonites along the western and southern shear zones, respectively, are interpreted as recording deformation in the ARSZ. The AFT ages, ranging from 15 to 5 Ma, represent a quiescent gap with a slow cooling/exhumation in the massif. AHe results suggest that a rapid cooling and final exhumation episode of the massif could have started before 3.2 Ma, or likely ca. 5 Ma, and continue to the present. The high-temperature horizontal shearing layers of the core were first formed across the Indochina Block, locally antiformed along the tectonic boundaries, and then cooled through the mica Ar-Ar closure temperature during Eocene or early Oligocene, subsequently reworked and further exhumed by sinistral strike-slip movement along the ARSZ during the early Oligocene (ca. 29 Ma), lasting until ca. 17 Ma, then final exhumation of the massif occurred by dextral normal faulting on the Weixi-Qiaohou and Red River faults along the limbs of the ARSZ since ca. 5 Ma. The formation of the antiform could indicate local crustal thickening in an early transpressional setting corresponding to India-Asia convergence. Large-scale sinistral ductile shear along the ARSZ in the shallow crust accommodated lateral extrusion of the Indochina Block, and further contributed to the vertical exhumation of the metamorphic massif from the late Oligocene to the middle Miocene. Furthermore, the change of kinematic reversal and associated cooling episodes along the ARSZ since the middle Miocene or early Pliocene imply a tectonic transfer from strain localization along the major tectonic boundaries to continuous deformation corresponding to plateau growth and expansion.
关键词	CENOZOIC TECTONIC EVOLUTION LEFT-LATERAL SHEAR STRIKE-SLIP TIBETAN PLATEAU DIANCANG SHAN WESTERN YUNNAN CONTINENTAL EXTRUSION STRUCTURAL EVOLUTION METAMORPHIC COMPLEX SOUTHEAST MARGIN
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000796184000001
来源期刊	GEOLOGICAL SOCIETY OF AMERICA BULLETIN
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/260744
推荐引用方式 GB/T 7714	Zhang, B.,Chen, S. Y.,Wang, Y.,et al. Crustal deformation and exhumation within the India-Eurasia oblique convergence zone: New insights from the Ailao Shan-Red River shear zone[J]. 中国科学院青藏高原研究所,2022,134(5-6).
APA	Zhang, B..,Chen, S. Y..,Wang, Y..,Reiners, P. W..,Cai, F. L..,...&Liu, K..(2022).Crustal deformation and exhumation within the India-Eurasia oblique convergence zone: New insights from the Ailao Shan-Red River shear zone.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,134(5-6).
MLA	Zhang, B.,et al."Crustal deformation and exhumation within the India-Eurasia oblique convergence zone: New insights from the Ailao Shan-Red River shear zone".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 134.5-6(2022).