scholarly journals Slab Dehydration and Mantle Upwelling in the Vicinity of the Sumatra Subduction Zone: Evidence from Receiver Function Imaging of Mantle Transition Zone Discontinuities

2020 ◽  
Vol 125 (9) ◽  
Author(s):  
Fansheng Kong ◽  
Stephen S. Gao ◽  
Kelly H. Liu ◽  
Weiwei Ding ◽  
Jiabiao Li
Keyword(s):  
Subduction Zone ◽  
Transition Zone ◽  
Receiver Function ◽  
Mantle Upwelling ◽  
Mantle Transition Zone ◽  
Slab Dehydration

Mantle transition zone discontinuities beneath the Indochina Peninsula: Implications for slab subduction and mantle upwelling

2017 ◽  
Vol 44 (14) ◽  
pp. 7159-7167 ◽  
Author(s):  
Youqiang Yu ◽  
Stephen S. Gao ◽  
Kelly H. Liu ◽  
Ting Yang ◽  
Mei Xue ◽  
...  
Keyword(s):  
Transition Zone ◽  
Mantle Upwelling ◽  
Indochina Peninsula ◽  
Mantle Transition Zone

scholarly journals Receiver function imaging of the mantle transition zone beneath the S outh C hina B lock

2015 ◽  
Vol 16 (10) ◽  
pp. 3666-3678 ◽  
Author(s):  
Haibo Huang ◽  
Nicola Tosi ◽  
Sung‐Joon Chang ◽  
Shaohong Xia ◽  
Xuelin Qiu
Keyword(s):  
Transition Zone ◽  
Receiver Function ◽  
Mantle Transition Zone

scholarly journals Tracing the subducting Pacific slab to the mantle transition zone with hydrogen isotopes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takeshi Kuritani ◽  
Kenji Shimizu ◽  
Takayuki Ushikubo ◽  
Qun-Ke Xia ◽  
Jia Liu ◽  
...  
Keyword(s):  
Transition Zone ◽  
Melt Inclusions ◽  
Hydrogen Isotopes ◽  
Volcanic Front ◽  
Mantle Transition Zone ◽  
Deep Interior ◽  
Terrestrial Water ◽  
Quantitative Understanding ◽  
Pacific Slab ◽  
Slab Dehydration

AbstractHydrogen isotopes have been widely used as powerful tracers to understand the origin of terrestrial water and the water circulation between the surface and the deep interior of the Earth. However, further quantitative understanding is hindered due to a lack of observations about the changes in D/H ratios of a slab during subduction. Here, we report hydrogen isotope data of olivine-hosted melt inclusions from active volcanoes with variable depths (90‒550 km) to the subducting Pacific slab. The results show that the D/H ratio of the slab fluid at the volcanic front is lower than that of the slab fluid just behind the volcanic front. This demonstrates that fluids with different D/H ratios were released from the crust and the underlying peridotite portions of the slab around the volcanic front. The results also show that the D/H ratios of slab fluids do not change significantly with slab depths from 300 to 550 km, which demonstrates that slab dehydration did not occur significantly beyond the arc. Our estimated δD‰ value for the slab materials that accumulated in the mantle transition zone is > − 90‰, a value which is significantly higher than previous estimates.

scholarly journals Seismic waveform tomography of the central and eastern Mediterranean upper mantle

Solid Earth ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 669-690 ◽  
Author(s):  
Nienke Blom ◽  
Alexey Gokhberg ◽  
Andreas Fichtner
Keyword(s):  
Subduction Zone ◽  
Transition Zone ◽  
Upper Mantle ◽  
High Velocity ◽  
Eastern Mediterranean ◽  
Crust And Upper Mantle ◽  
Mantle Transition Zone ◽  
Seismic Waveform ◽  
Waveform Tomography ◽  
Seismic Waveform Tomography

Abstract. We present a seismic waveform tomography of the upper mantle beneath the central and eastern Mediterranean down to the mantle transition zone. Our methodology incorporates in a consistent manner the information from body and multimode surface waves, source effects, frequency dependence, wavefront healing, anisotropy and attenuation. This allows us to jointly image multiple parameters of the crust and upper mantle. Based on the data from ∼ 17 000 unique source–receiver pairs, gathered from 80 earthquakes, we image radially anisotropic S velocity, P velocity and density. We use a multi-scale approach in which the longest periods (100–150 s) are inverted first, broadening to a period band of 28–150 s. Thanks to a strategy that combines long-period signals and a separation of body and surface wave signals, we are able to image down to the mantle transition zone in most of the model domain. Our model shows considerable detail in especially the northern part of the domain, where data coverage is very dense, and displays a number of clear and coherent high-velocity structures across the domain that can be linked to episodes of current and past subduction. These include the Hellenic subduction zone, the Cyprus subduction zone and high-velocity anomalies beneath the Italian peninsula and the Dinarides. This model is able to explain data from new events that were not included in the inversion.

Foundered lithospheric segments dropped into the mantle transition zone beneath southern California, USA

Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 200-204
Author(s):  
Youqiang Yu ◽  
Stephen S. Gao ◽  
Kelly H. Liu ◽  
Dapeng Zhao
Keyword(s):  
Transition Zone ◽  
Sierra Nevada ◽  
Southern California ◽  
Receiver Function ◽  
Active Tectonics ◽  
Mantle Transition Zone ◽  
Diverse Range ◽  
Transverse Ranges ◽  
The Pacific ◽  
Lateral Variations

Abstract The diverse range of active tectonics occurring in southern California, USA, offers an opportunity to explore processes of continental deformation and modification in response to the instability of the Pacific and Farallon plates. Here, we present a high-resolution receiver-function image of the mantle transition zone (MTZ). Our result reveals significant lateral heterogeneities in the deep mantle beneath southern California. Both seismic tomography and MTZ discontinuity deflections reveal foundered lithospheric segments that have dropped into the MTZ beneath the western Transverse Ranges, the Peninsular Ranges, and part of the southern Sierra Nevada. Water dehydrated from these foundered materials may contribute to the observed MTZ thickening. Our observations, combined with previous tomography and geochemical results, indicate that lithospheric foundering of fossil arc roots provides a way for geochemical heterogeneities to be recycled into the underlying mantle, and suggest that the foundered materials can play a significant role in inducing lateral variations of MTZ structure.

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