气候变化领域集成服务门户(CCPortal): Lithospheric Delamination Beneath the Southern Puna Plateau Resolved by Local Earthquake Tomography

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DOI	10.1029/2019JB019040
	Lithospheric Delamination Beneath the Southern Puna Plateau Resolved by Local Earthquake Tomography
	Chen J.; Kufner S.-K.; Yuan X.; Heit B.; Wu H.; Yang D.; Schurr B.; Kay S.
发表日期	2020
ISSN	21699313
卷号	125 期号:10
英文摘要	We present a local earthquake tomography to illuminate the crustal and uppermost mantle structure beneath the southern Puna plateau and to test the delamination hypothesis. Vp and Vp/Vs ratios were obtained using travel time variations recorded by 75 temporary seismic stations between 2007 and 2009. In the upper crust, prominent low Vp anomalies are found beneath the main volcanic centers, indicating the presence of magma and melt beneath the southern Puna plateau. Beneath the Moho at around 90-km depth, a strong high Vp anomaly is detected just west of the giant backarc Cerro Galan ignimbrite caldera. This high Vp anomaly is only resolved if earthquakes with an azimuthal gap up to 300° are included in the inversion. However, we show through data subset and synthetic tests that the anomaly is robust due to our specific station-event geometry and interpret it as a delaminated block of lower crust and uppermost mantle lithosphere under the southern Puna plateau. The low velocities in the crust are interpreted as a product of the delamination event that triggered the rise of fluids and melts into the crust and induced the high topography in this part of the plateau. The tomography also reveals the existence of low-velocity anomalies that link arc magmatism at the Ojos del Salado volcanic center with slab seismicity clusters at depths of about 100 and 150 km and support fluid transport in the mantle wedge due to dehydration reaction within the subducted slab. ©2020. The Authors.
英文关键词	crustal melt accumulation; lithospheric delamination; local earthquake tomography; slab dehydration; southern Puna plateau
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187531
作者单位	Department of Mathematical Science, Tsinghua University, Beijing, China; Deutsches GeoForschungsZentrum GFZ, Potsdam, Germany; Ice Dynamics and Palaeoclimate team, British Antarctica Survey, Cambridge, United Kingdom; Department of Earth and Atmospheric Science, Cornell University, Ithaca, NY, United States
推荐引用方式 GB/T 7714	Chen J.,Kufner S.-K.,Yuan X.,et al. Lithospheric Delamination Beneath the Southern Puna Plateau Resolved by Local Earthquake Tomography[J],2020,125(10).
APA	Chen J..,Kufner S.-K..,Yuan X..,Heit B..,Wu H..,...&Kay S..(2020).Lithospheric Delamination Beneath the Southern Puna Plateau Resolved by Local Earthquake Tomography.Journal of Geophysical Research: Solid Earth,125(10).
MLA	Chen J.,et al."Lithospheric Delamination Beneath the Southern Puna Plateau Resolved by Local Earthquake Tomography".Journal of Geophysical Research: Solid Earth 125.10(2020).