Numerical modeling of deep oceanic slab dehydration: Implications for the possible origin of far field intra-continental volcanoes in northeastern China

Sheng, Jian; Liao, Jie; Gerya, Taras

doi:10.1016/j.jseaes.2015.12.022

Cited by 21 publications

(7 citation statements)

References 54 publications

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“…Thus, deep storage and recycling over billions of years may not be the only way in which extreme isotopic domains develop in the mantle (Mazza et al, 2019). Two-dimensional geodynamic numerical models suggest that the volatile-rich top layer of the MTZ was sampled by disturbances related to mantle flow induced by dehydration of a stagnant slab (Sheng et al, 2016). Furthermore, sublithospheric small-scale convection readily entrains the volatile-rich materials near the base of the lithosphere, resulting in mantle melting and intraplate volcanism (Figure 4).…”

Section: The Possible Genetic Model For the Himu Mantle Sourcementioning

confidence: 99%

The Mantle Transition Zone Hosts the Missing HIMU Reservoir Beneath Eastern China

Qian

Nichols

et al. 2020

Geophysical Research Letters

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The Earth's mantle shows large-scale geochemical heterogeneities bounded by several identifiable end-member compositions. However, the origin of extreme mantle reservoirs, for example, high 238 U/ 204 Pb (HIMU), and their location in the Earth's interior remains poorly constrained. Clinopyroxenes from late Cenozoic Wudi lavas in eastern China have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. Our new results provide, to our knowledge, the first evidence for the existence of a HIMU-like component in the sources of late Cenozoic lavas. Analyses of olivines and their host lavas indicate that the basaltic melts are derived from partial melting of carbonated peridotite. The HIMU source is likely to be younger than 700 Ma old and related to subduction events of the Paleo-Asian ocean. In addition to deep and ancient recycling, storage of a metasomatically produced mantle reservoir in the mantle transition zone may be an important mechanism for developing extreme isotopic signatures.

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Section: The Possible Genetic Model For the Himu Mantle Sourcementioning

confidence: 99%

The Mantle Transition Zone Hosts the Missing HIMU Reservoir Beneath Eastern China

Qian

Nichols

et al. 2020

Geophysical Research Letters

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“…Numerical modeling suggested that as a result of a hydrated slab lingering in the transition zone, a hydrous layer of low density and viscosity could form at the top of the slab and lead to a small‐scale convection and instabilities. Such instabilities were shown to merge together and form (xi) a “wet plume,” which could reach the base of the lithosphere and produce melt as a result of water‐lowered solidus [ Sheng et al , ; Richard and Bercovici , ; Richard and Iwamori , ].…”

Section: Discussionmentioning

confidence: 99%

Full‐waveform inversion of the Japanese Islands region

et al. 2016

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We present a full‐waveform tomographic model of the crust and upper mantle beneath the Japanese Islands region. This is based on the combination of GPU‐accelerated spectral‐element wavefield simulations, adjoint techniques, and nonlinear optimization. Our model explains complete seismic waveforms of events not used in the inversion in the period range from 20 to 80 s. Quantitative resolution analysis indicates that resolution lengths within the well‐covered areas are around 150 km in the horizontal and around 30 km in the vertical directions. In addition to the high‐velocity signatures of known lithospheric slabs in the region, our model reveals a pronounced low‐velocity anomaly beneath the volcanic island of Ulleung in the Sea of Japan, reaching −19% around 100 km depth. The Ulleung anomaly originates at or above the Pacific slab, rises vertically upward to the base of the Philippine Sea slab at ∼200 km depth, circumvents it in NW direction, and then significantly strengthens in the uppermost mantle above the Philippine Sea slab. Among the numerous hypotheses for the generation of low‐velocity anomalies in subduction systems, those invoking instabilities before or when a slab enters the transition zone seem most likely. The age and fast subduction of the Pacific slab may facilitate the transport of fluids into the transition zone. This may promote the reduction in viscosity and the onset of convective upwelling, aided by ambient mantle flow, such as return flow within the mantle wedge.

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“…Internal velocity boundary conditions (i.e., intraplate push) are used in our models during the first 10 Ma to initiate self-sustained subduction. During this time, the subducting and overriding plates are pushed towards each other with the velocity at x = 850 km and x = 3,000 km (for the initial velocity of slab, see Table 2), respectively (Sheng, Liao, & Gerya, 2016).…”

Section: Boundary Conditionsmentioning

confidence: 99%

“…The most likely reason for the fast slab retreat rates of our models at developing stage is the steep subducting slab dip angle, which provides more downgoing force to accelerate the subduction. Another reason might be in part due to more hot mantle upwellings into the neck and the stretched underlying continental lithosphere, which favours to accelerate thinning and weakening the continental slab, eventually leads to fasten back-arc extension and the slab retreat (Dai, Li, Li, Somerville, & Liu, 2017;Dai et al, 2018;Sheng et al, 2016).…”

Section: Slab Retreatmentioning

confidence: 99%

Dynamics of back‐arc extension controlled by subducting slab retreat: Insights from 2D thermo‐mechanical modelling

Sheng

Liao

et al. 2018

Geological Journal

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Back‐arc regions, located in the overriding slabs and separated from fore‐arcs by magmatic extrusion, are closely coupled with subduction zones. The width of back‐arc extension is broadly varied in the world. Although the dynamics of the subducting slab is widely studied, the coupling between subducting slab dynamics and back‐arc extension development is still poorly understood. In this study, we aim to numerically analyse how subducting slab retreat influences back‐arc extension, with particular attention paid on the coupling between subducting slab dynamics and back‐arc extension dynamics. Geometry evolution of the subducting slab in the deep upper mantle is investigated. Furthermore, we investigate key parameters that may control back‐arc extension dynamic pattern and process. We perform systematically a set of numerical experiments with 2D high‐resolution thermo‐mechanical coupled oceanic–continental subduction models.

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Numerical modeling of deep oceanic slab dehydration: Implications for the possible origin of far field intra-continental volcanoes in northeastern China

Cited by 21 publications

References 54 publications

The Mantle Transition Zone Hosts the Missing HIMU Reservoir Beneath Eastern China

The Mantle Transition Zone Hosts the Missing HIMU Reservoir Beneath Eastern China

Full‐waveform inversion of the Japanese Islands region

Dynamics of back‐arc extension controlled by subducting slab retreat: Insights from 2D thermo‐mechanical modelling

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