Mantle response to ridge re-organization ...
The local preservation of depleted Nd-Hf and Os isotopic compositions in abyssal peridotites contrasts with the lack of such extreme isotopic signatures in erupted MORB [1]. This is likely a consequence of different preservation potentials of melts from enriched and depleted portions of mantle [2]....
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| Format: | Text |
| Language: | English |
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Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
2022
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| Online Access: | https://dx.doi.org/10.48380/xp90-ay88 https://www.dggv.de/e-publikationen/mantle-response-to-ridge-re-organization |
| Summary: | The local preservation of depleted Nd-Hf and Os isotopic compositions in abyssal peridotites contrasts with the lack of such extreme isotopic signatures in erupted MORB [1]. This is likely a consequence of different preservation potentials of melts from enriched and depleted portions of mantle [2]. Indeed, fertile and geochemically enriched components produce melts hosting the majority of incompatible elements, concealing the chemical fingerprint of the depleted counterparts [3]. However, Mid Ocean Ridges are dynamic environments, where geodynamic responses to far field forces may cause change in ridge-geometry and/or re-organization of the ridge axis. This contribution discusses how this process affects melting regimes, reducing the effect of mixing [5,6]. I will consider study cases from large-offset oceanic transforms from the Mid Atlantic Ridge (Doldrums and Charlie Gibbs Fracture Zones), and from the highly asymmetric Knipovich Ridge, in the Arctic Ocean. Variations in chemistry of basalt and associated ... |
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