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Barrat, Jean-alix; Ferrière, L.. |
Main-group pallasites (MGPs) are meteorites mainly composed of Fe-Ni metal and olivines, the latter being considered as one of the largest sampling of extraterrestrial mantle material available for study on Earth. We analysed the rare earth element (REE) concentrations of olivines from six MGPs to understand better the processes of formation of their parent mantle. All the investigated samples display very low REE abundances, and enrichments in both light REEs and heavy REEs. We interpret the light REE enrichments as a fingerprint of terrestrial contamination. The least contaminated olivines have higher heavy REE enrichments than those inferred for olivines directly crystallised in a magma ocean. Such enrichments in heavy REEs are possible if the mantle of... |
Tipo: Text |
Palavras-chave: Pallasite; Early solar system; Trace elements; Rare earth elements; Differentiation. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79770/82569.pdf |
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Bischoff, Addi; Alexander, Conel M. O'D; Barrat, Jean-alix; Burkhardt, Christoph; Busemann, Henner; Degering, Detlev; Di Rocco, Tommaso; Fischer, Meike; Fockenberg, Thomas; Foustoukos, Dionysis, I; Gattacceca, Jerome; Godinho, Jose R. A.; Harries, Dennis; Heinlein, Dieter; Hellmann, Jan L.; Hertkorn, Norbert; Holm, Anja; Jull, A. J. Timothy; Kerraouch, Imene; King, Ashley J.; Kleine, Thorsten; Koll, Dominik; Lachner, Johannes; Ludwig, Thomas; Merchel, Silke; Mertens, Cornelia A. K.; Morino, Precillia; Neumann, Wladimir; Pack, Andreas; Patzek, Markus; Pavetich, Stefan; Reitze, Maximilian P.; Rufenacht, Miriam; Rugel, Georg; Schmidt, Charlotte; Schmitt-kopplin, Philippe; Schonbachler, Maria; Trieloff, Mario; Wallner, Anton; Wimmer, Karl; Woelfer, Elias. |
On September 12, 2019 at 12:49:48 (UT) a bolide was observed by hundreds of eye-witnesses from the Netherlands, Germany, Belgium, Denmark and the UK. One day later a small meteorite stone was found by accident in Flensburg. The presence of short-lived cosmogenic radionuclides with half-lives as short as 16 days proves the recent exposure of the found object to cosmic rays in space linking it clearly to the bolide event. An exceptionally short exposure time of similar to 5000 years was determined. The 24.5 g stone has a fresh black fusion crust, a low density of <2 g/cm(3), and a magnetic susceptibility of log chi = 4.35 (chi in 10(-9) m(3)/kg). The rock consists of relict chondrules and clusters of sulfide and magnetite grains set in a fine-grained... |
Tipo: Text |
Palavras-chave: C1 chondrite; Carbonaceous chondrite; Aqueous alteration; Carbonates; Early solar system; Oldest carbonates in solar system; Unique chondrite; Ungrouped C chondrite. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79845/82672.pdf |
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