Continental flood basalts derived from the hydrous mantle transition zone
MetadataShow full item record
It has previously been postulated that the Earth's hydrous mantle transition zone may play a key role in intraplate magmatism, but no confirmatory evidence has been reported. Here we demonstrate that hydrothermally altered subducted oceanic crust was involved in generating the late Cenozoic Chifeng continental flood basalts of East Asia. This study combines oxygen isotopes with conventional geochemistry to provide evidence for an origin in the hydrous mantle transition zone. These observations lead us to propose an alternative thermochemical model, whereby slab-triggered wet upwelling produces large volumes of melt that may rise from the hydrous mantle transition zone. This model explains the lack of pre-magmatic lithospheric extension or a hotspot track and also the arc-like signatures observed in some large-scale intracontinental magmas. Deep-Earth water cycling, linked to cold subduction, slab stagnation, wet mantle upwelling and assembly/breakup of supercontinents, can potentially account for the chemical diversity of many continental flood basalts.
This open access article is distributed under the Creative Commons license http://creativecommons.org/licenses/by/4.0/
Showing items related by title, author, creator and subject.
Initial breakup of supercontinent Rodinia as recorded by ca 860–840 Ma bimodal volcanism along the southeastern margin of the Yangtze Block, South ChinaLyu, P.; Li, W.; Wang, Xuan-Ce; Pang, C.; Cheng, J.; Li, X. (2017)Abstract It is considered that mantle plumes play an important role in the breakup of supercontinents, but continental rifting and associated bimodal volcanism often predate mantle-plume magmatism and the major stage of ...
Pigott, J.; Wright, Kathleen; Gale, Julian; Panero, W. (2015)Interpretation of lateral variations in upper mantle seismic wave speeds requires constraints on the relationship between elasticity and water concentration at high pressure for all major mantle minerals, including the ...
Ivanic, T.; Nebel, O.; Jourdan, Fred; Faure, K.; Kirkland, Chris; Belousova, E. (2015)Archean mafic-ultramafic melts, crystallized as layered intrusions in the upper crust and extruded as komatiitic flows, are primary probes of upper mantle chemistry. However, the message from their primary chemical ...