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Amagmatic Subduction Produced by Mantle Serpentinization and Oceanic Crust Delamination
Author(s) -
Yang Jianfeng,
Lu Gang,
Liu Tong,
Li Yang,
Wang Kun,
Wang Xinxin,
Sun Baolu,
Faccenda Manuele,
Zhao Liang
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl086257
Subject(s) - geology , subduction , mantle (geology) , oceanic crust , mantle wedge , crust , lithosphere , volcanic arc , geochemistry , adakite , magmatism , geophysics , transition zone , continental crust , petrology , seismology , tectonics
Recycling of oceanic lithosphere and serpentinized peridotites into the mantle leads to dehydration melting and volcanic arcs. However, the mechanism of the occurrence of long‐term volcanic gap in subduction zones remains poorly understood. Two‐dimensional thermomechanical numerical models focusing on resisting the transport of the major hosts of hydrous minerals to mantle depths, show that thin oceanic crust together with rheologically weak and buoyant serpentinized mantle could result in hydrated lithologies piling up in the accretionary wedge and no or sparse occurrence of arc magmatism. This scenario may occur during subduction of oceanic lithosphere formed at (ultra)slow‐spreading margins characterized by thin crust and extensive mantle serpentinization, which is a plausible explanation for the “arc gaps” in the Alps and southern Tibet.