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DOI	10.1016/j.tecto.2024.230209
	The structure of the mantle transition zone and its implications for mantle upwelling beneath the central Tibetan plateau from triplicated P-waveforms modeling
	Lv, Miaomiao; Xu, Xiaoming; Ding, Zhifeng
发表日期	2024
ISSN	0040-1951
EISSN	1879-3266
起始页码	872
卷号	872
英文摘要	The Tibetan plateau is considered as an ideal place for studying the continental collisions, tectonic movements and regional geodynamics. Although multiple episodes of igneous activities in Tibetan plateau have been suggested derived from mantle upwelling, their origins and corresponding geodynamic models remain vigorously debate. This study presents a high -resolution upper mantle velocity model of P -wave and its lateral variation beneath the central Tibetan plateau based on triplicated waveform modeling. The results show that, compared with IASP91 model, the 660 -km discontinuity is deepened approximately 17-28 km from the Qiangtang terrane to the Beishan block. The lower mantle transition zone (MTZ) is characterized by high P -wave velocity anomalies (HVA) in range of 0.3%-0.9%. We infer that they are mainly related to the hydrous materials with low temperature in the lower MTZ. Besides, the depression of the 410 -km discontinuity is about 6-15 km. A remarkable low velocity layer (LVL) is detected atop the 410 -km discontinuity, exhibiting the thickness of 31-40 km and low P -wave velocity anomaly of -2.5% to -1.6%. This is against completely temperature -dominated origin of the LVL, and suggests that the material composition has also contributes. Additionally, we propose a new geodynamic model to demonstrate the asthenospheric upwelling beneath the Qiangtang and Songpan-Ganzi terranes, which suggests that the passively ascending water -enriched materials from the lower MTZ and their dehydration are responsible for the observed LVL atop the 410 -km discontinuity, as well as the origin of the Cenozoic magmatic intrusion and volcanic eruption of the northern Tibet volcano in Pleistocene.
英文关键词	Central Tibetan plateau; Triplicated waveform modeling; Mantle transition zone; Low velocity layer; Mantle upwelling
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001165529900001
来源期刊	TECTONOPHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/303622
作者单位	China Earthquake Administration
推荐引用方式 GB/T 7714	Lv, Miaomiao,Xu, Xiaoming,Ding, Zhifeng. The structure of the mantle transition zone and its implications for mantle upwelling beneath the central Tibetan plateau from triplicated P-waveforms modeling[J],2024,872.
APA	Lv, Miaomiao,Xu, Xiaoming,&Ding, Zhifeng.(2024).The structure of the mantle transition zone and its implications for mantle upwelling beneath the central Tibetan plateau from triplicated P-waveforms modeling.TECTONOPHYSICS,872.
MLA	Lv, Miaomiao,et al."The structure of the mantle transition zone and its implications for mantle upwelling beneath the central Tibetan plateau from triplicated P-waveforms modeling".TECTONOPHYSICS 872(2024).