A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume
Abstract Deep subduction of plate generally could induce a partial molten low‐velocity layer (LVL) atop the mantle transition zone (MTZ) around the subduction zone. But the effects of the LVL to its upper lithosphere are less known, especially at the oceanward direction of subducted slab. Here, we i...
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Online Access: | https://doi.org/10.1029/2021GC010150 https://doaj.org/article/6e2872eaa1514a72a7c613a3e1c7a809 |
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ftdoajarticles:oai:doaj.org/article:6e2872eaa1514a72a7c613a3e1c7a809 2023-12-03T10:31:55+01:00 A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume Guohui Li Yuanze Zhou Lin Ding Yuan Gao Ling Bai Heng Zhang Le Hu Zhengyang Pan Changhui Ju Dingding Zhang 2022-02-01T00:00:00Z https://doi.org/10.1029/2021GC010150 https://doaj.org/article/6e2872eaa1514a72a7c613a3e1c7a809 EN eng Wiley https://doi.org/10.1029/2021GC010150 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2021GC010150 https://doaj.org/article/6e2872eaa1514a72a7c613a3e1c7a809 Geochemistry, Geophysics, Geosystems, Vol 23, Iss 2, Pp n/a-n/a (2022) low‐velocity layer mantle transition zone triplicated waveform modeling plate subduction mantle plume western Junggar Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.1029/2021GC010150 2023-11-05T01:35:57Z Abstract Deep subduction of plate generally could induce a partial molten low‐velocity layer (LVL) atop the mantle transition zone (MTZ) around the subduction zone. But the effects of the LVL to its upper lithosphere are less known, especially at the oceanward direction of subducted slab. Here, we image the seismic velocity structure atop the MTZ by matching the synthetics and the observed triplicated P‐ and SH‐wave waveforms recorded by Xinjiang seismic network from four earthquakes in the southwestern Siberia. Our observations reveal a partial molten LVL atop the MTZ beneath the western Junggar (WJ) in the southwestern Central Asian Orogenic Belt. The SH‐wave velocity drop for the LVL is −5.6% which is larger than −4.4% of the P‐wave when its thickness is 29 km. It is inferred that the subducted Paleo‐Asian oceanic plate induces hydrous MTZ materials underneath the subducted slab to upwell to the upper mantle, and form the partial molten LVL. Combined with previous geophysical and geological results, we propose a new geodynamical process involving the lithosphere and MTZ underneath the subducted slab: the melt in the LVL is likely to upwell through slab window, which could be triggered by mid‐oceanic ridge subduction or self‐sustained buoyancy. This mode could account for the contemporaneous break‐off fossil oceanic plate, ocean island basalts‐type rocks, extensive A‐type granitoids, adakite, and porphyry Cu‐Au in the WJ during the late Carboniferous to early Permian. Article in Journal/Newspaper Ocean Island Siberia Directory of Open Access Journals: DOAJ Articles Geochemistry, Geophysics, Geosystems 23 2 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
low‐velocity layer mantle transition zone triplicated waveform modeling plate subduction mantle plume western Junggar Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
low‐velocity layer mantle transition zone triplicated waveform modeling plate subduction mantle plume western Junggar Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Guohui Li Yuanze Zhou Lin Ding Yuan Gao Ling Bai Heng Zhang Le Hu Zhengyang Pan Changhui Ju Dingding Zhang A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
topic_facet |
low‐velocity layer mantle transition zone triplicated waveform modeling plate subduction mantle plume western Junggar Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract Deep subduction of plate generally could induce a partial molten low‐velocity layer (LVL) atop the mantle transition zone (MTZ) around the subduction zone. But the effects of the LVL to its upper lithosphere are less known, especially at the oceanward direction of subducted slab. Here, we image the seismic velocity structure atop the MTZ by matching the synthetics and the observed triplicated P‐ and SH‐wave waveforms recorded by Xinjiang seismic network from four earthquakes in the southwestern Siberia. Our observations reveal a partial molten LVL atop the MTZ beneath the western Junggar (WJ) in the southwestern Central Asian Orogenic Belt. The SH‐wave velocity drop for the LVL is −5.6% which is larger than −4.4% of the P‐wave when its thickness is 29 km. It is inferred that the subducted Paleo‐Asian oceanic plate induces hydrous MTZ materials underneath the subducted slab to upwell to the upper mantle, and form the partial molten LVL. Combined with previous geophysical and geological results, we propose a new geodynamical process involving the lithosphere and MTZ underneath the subducted slab: the melt in the LVL is likely to upwell through slab window, which could be triggered by mid‐oceanic ridge subduction or self‐sustained buoyancy. This mode could account for the contemporaneous break‐off fossil oceanic plate, ocean island basalts‐type rocks, extensive A‐type granitoids, adakite, and porphyry Cu‐Au in the WJ during the late Carboniferous to early Permian. |
format |
Article in Journal/Newspaper |
author |
Guohui Li Yuanze Zhou Lin Ding Yuan Gao Ling Bai Heng Zhang Le Hu Zhengyang Pan Changhui Ju Dingding Zhang |
author_facet |
Guohui Li Yuanze Zhou Lin Ding Yuan Gao Ling Bai Heng Zhang Le Hu Zhengyang Pan Changhui Ju Dingding Zhang |
author_sort |
Guohui Li |
title |
A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
title_short |
A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
title_full |
A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
title_fullStr |
A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
title_full_unstemmed |
A Partial Molten Low‐Velocity Layer Atop the Mantle Transition Zone Beneath the Western Junggar: Implication for the Formation of Subduction‐Induced Sub‐Slab Mantle Plume |
title_sort |
partial molten low‐velocity layer atop the mantle transition zone beneath the western junggar: implication for the formation of subduction‐induced sub‐slab mantle plume |
publisher |
Wiley |
publishDate |
2022 |
url |
https://doi.org/10.1029/2021GC010150 https://doaj.org/article/6e2872eaa1514a72a7c613a3e1c7a809 |
genre |
Ocean Island Siberia |
genre_facet |
Ocean Island Siberia |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 23, Iss 2, Pp n/a-n/a (2022) |
op_relation |
https://doi.org/10.1029/2021GC010150 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2021GC010150 https://doaj.org/article/6e2872eaa1514a72a7c613a3e1c7a809 |
op_doi |
https://doi.org/10.1029/2021GC010150 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
23 |
container_issue |
2 |
_version_ |
1784258468802199552 |