dc.contributor.author | Bjerga, Anders | |
dc.contributor.author | Stubseid, Håvard Hallås | |
dc.contributor.author | Pedersen, Leif-Erik Rydland | |
dc.contributor.author | Beinlich, Andreas Michael | |
dc.contributor.author | Pedersen, Rolf B. | |
dc.date.accessioned | 2023-03-01T13:33:11Z | |
dc.date.available | 2023-03-01T13:33:11Z | |
dc.date.created | 2022-12-14T10:19:33Z | |
dc.date.issued | 2022 | |
dc.identifier.issn | 1525-2027 | |
dc.identifier.uri | https://hdl.handle.net/11250/3055043 | |
dc.description.abstract | The Mohns Ridge is a very slow-spreading ridge that, together with the Knipovich Ridge, marks the boundary between the North American and Eurasian plates in the Norwegian-Greenland Sea. In this study, we report the major and trace element composition of spatially associated basalts and peridotites from a gabbro-peridotite complex ∼20 km west of the Mohns Ridge rift flank. Formation of the ∼4–5 Myr crustal section involved accretion of normal mid-ocean ridge basalts with Na-content suggesting derivation from a depleted mantle source. This is consistent with the degree of partial melting estimated for clinopyroxene poor harzburgites using the Cr-number of spinel (14%–18%) and rare earth element modeling of orthopyroxene (16%–24%) and reconstructed whole-rock composition (14%–20%). If all the melting took place beneath the paleo-Mohns Ridge, a crustal thickness of ∼7–8 km is expected, which is nearly double the observed thickness. Orthopyroxene trace elements are not consistent with typical fractional melting expected for mid-ocean ridges but rather resemble that seen in supra-subduction zone peridotites. The geochemistry of both the basalts and the peridotites suggests that a water-rich slab flux in the past has influenced the mantle source. In turn, this caused hydrous melting which increased the depletion of the pyroxene components, leading to a highly depleted mantle that is now underlying much of the Arctic Mid-Ocean Ridges and represents the source for the spreading related magmatism. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | AGU | en_US |
dc.rights | Navngivelse 4.0 Internasjonal | * |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/deed.no | * |
dc.title | A Highly Depleted and Subduction-Modified Mantle Beneath the Slow-Spreading Mohns Ridge | en_US |
dc.type | Journal article | en_US |
dc.type | Peer reviewed | en_US |
dc.description.version | publishedVersion | en_US |
dc.rights.holder | Copyright 2022 The Author(s) | en_US |
dc.source.articlenumber | e2022GC010585 | en_US |
cristin.ispublished | true | |
cristin.fulltext | original | |
cristin.qualitycode | 1 | |
dc.identifier.doi | 10.1029/2022GC010585 | |
dc.identifier.cristin | 2092903 | |
dc.source.journal | Geochemistry Geophysics Geosystems | en_US |
dc.identifier.citation | Geochemistry Geophysics Geosystems. 2022, 23 (11), e2022GC010585. | en_US |
dc.source.volume | 23 | en_US |
dc.source.issue | 11 | en_US |