气候变化领域集成服务门户(CCPortal): The Early Cretaceous Zaduo Granite, Eastern Qiangtang Terrane (China)-An Attempt to Constrain its Paleolatitude and Tectonic Implications

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DOI	10.3389/feart.2022.829593
	The Early Cretaceous Zaduo Granite, Eastern Qiangtang Terrane (China)-An Attempt to Constrain its Paleolatitude and Tectonic Implications
	Fu, Qiang; Yan, Maodu; Dekkers, Mark J.; Guan, Chong; de Boer, Rosa A.; Yu, Liang; Xu, Wanlong; Li, Bingshuai; Shen, Miaomiao; Zhang, Jingyu; Xu, Zunbo
通讯作者	Yan, MD (通讯作者)
发表日期	2022
EISSN	2296-6463
卷号	10
英文摘要	The Eastern Qiangtang Terrane is an orogenic-like belt around the Eastern Himalayan syntaxis (EHS). The deformation history of this terrane must be known to understand how the EHS region responded to the Lhasa-Qiangtang collision and the closure of the Bangong-Nujiang Ocean (BNO). Here, we present a new paleomagnetic investigation on an Early Cretaceous granite (& SIM;126 Ma) in the Zaduo area, Eastern Qiangtang Terrane. Petrographic observations reflect crystallization from primary melts with only limited subsequent alteration (chloritization of biotite). Magnetite appears to be the dominant carrier of the characteristic remanent magnetization (ChRM) based on stepwise demagnetization of the natural remanent magnetization, supplemented by detailed rock magnetic measurements, including magnetization versus temperature, and acquisition curves of the isothermal and anhysteretic remanent magnetization. End-member modeling of those acquisition curves helped to constrain the paleomagnetic analysis. The inconsistent demagnetization behavior between alternating field (AF) demagnetization at high levels and thermal demagnetization was attributed to the development of gyroremanent magnetization in the AF demagnetization generated by fine-grained single domain magnetite. The ChRM directions from 92 granite samples in geographic coordinates yield an average of declination (Dg) of 2.6 & DEG; and inclination (Ig) of 38.6 & DEG; (precision parameter k = 51.4, and 95% confidence cone alpha(95) = 2.1 & DEG;). The amount of tilting of the granite is poorly constrained which makes proper correction rather tedious. We compared the expected bedding attitudes (Strike(exp) = 43.1 & DEG;, Dip(exp) = 46.1 & DEG;) derived from published data (Huang et al., 1992; Tong et al., 2015) with the average observed bedding attitudes (Strike(obs) = 54 & DEG;, Dip(obs) = 32 & DEG;) of the Middle-Upper Jurassic sandstones of the Yanshiping Group that was intruded by the Early Cretaceous granite. The discrepancy between the expected and measured bedding attitudes implies that the strata of the Yanshiping Group in the Zaduo area were already tilted prior to the intrusion of the & SIM;126 Ma Zaduo granite, which was attributed to the Lhasa-Qiangtang collision and the closure of the BNO. The collision led to a series of geological events, such as the tilting of the strata, the ophiolite emplacement, the development of a peripheral foreland basin, and the magmatic activity gap. The tilting/folding of the strata was generally delayed by the layer parallel shortening processes during the early stages of the deformation, thus suggesting an older Lhasa-Qiangtang collision (i.e., > 126 Ma).
关键词	ALTERNATING-FIELD DEMAGNETIZATION REMANENT MAGNETIZATION RRM NUJIANG TETHYAN OCEAN U-PB GEOCHRONOLOGY CENTRAL TIBET GYROREMANENT MAGNETIZATION LHASA-QIANGTANG PALEOMAGNETIC CONSTRAINTS ACQUISITION CURVES GYROMAGNETIC REMANENCE
英文关键词	paleomagnetism; Lhasa-Qiangtang collision; cretaceous granite; end-member modeling; Tibeten Plateau
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000761082300001
来源期刊	FRONTIERS IN EARTH SCIENCE
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/260724
推荐引用方式 GB/T 7714	Fu, Qiang,Yan, Maodu,Dekkers, Mark J.,et al. The Early Cretaceous Zaduo Granite, Eastern Qiangtang Terrane (China)-An Attempt to Constrain its Paleolatitude and Tectonic Implications[J]. 中国科学院青藏高原研究所,2022,10.
APA	Fu, Qiang.,Yan, Maodu.,Dekkers, Mark J..,Guan, Chong.,de Boer, Rosa A..,...&Xu, Zunbo.(2022).The Early Cretaceous Zaduo Granite, Eastern Qiangtang Terrane (China)-An Attempt to Constrain its Paleolatitude and Tectonic Implications.FRONTIERS IN EARTH SCIENCE,10.
MLA	Fu, Qiang,et al."The Early Cretaceous Zaduo Granite, Eastern Qiangtang Terrane (China)-An Attempt to Constrain its Paleolatitude and Tectonic Implications".FRONTIERS IN EARTH SCIENCE 10(2022).