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| Deng, Zhengbin; Moynier, Frederic; Villeneuve, Johan; Jensen, Ninna K.; Liu, Deze; Cartigny, Pierre; Mikouchi, Takashi; Siebert, Julien; Agranier, Arnaud; Chaussidon, Marc; Bizzarro, Martin. |
| Despite the abundant geomorphological evidence for surface liquid water on Mars during the Noachian epoch (>3.7 billion years ago), attaining a warm climate to sustain liquid water on Mars at the period of the faint young Sun is a long-standing question. Here, we show that melts of ancient mafic clasts from a martian regolith meteorite, NWA 7533, experienced substantial Fe-Ti oxide fractionation. This implies early, impact-induced, oxidation events that increased by five to six orders of magnitude the oxygen fugacity of impact melts from remelting of the crust. Oxygen isotopic compositions of sequentially crystallized phases from the clasts show that progressive oxidation was due to interaction with an O-17-rich water reservoir. Such an early oxidation... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00686/79855/82697.pdf |
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| Zhu, Ke; Moynier, Frederic; Wielandt, Daniel; Larsen, Kirsten K.; Barrat, Jean-alix; Bizzarro, Martin. |
| Angrite meteorites are some of the oldest materials in the solar system. They provide important information on the earliest evolution of the solar system and accretion timescales of protoplanets. Here, we show that the Cr-54/Cr-52 ratio is homogeneously distributed among angrite meteorites within 13 parts per million, indicating that precursor materials must have experienced a global-scale melting such as a magma ocean. The Cr-53/Cr-52 and Mn/Cr ratios are correlated, which is evidence for an initial Mn-53/Mn-55 ratio of (3.16 +/- 0.11) x 10(-6). When anchored to the U-corrected Pb-Pb age for the D'Orbigny angrite, this initial 53Mn/55Mn corresponds to an absolute age of 4563.2 +/- 0.3 Ma, i.e., 4.1 +/- 0.3 Ma after Ca-Al-rich inclusion-formation. This age... |
| Tipo: Text |
Palavras-chave: Astrochemistry meteorites; Meteors; Meteoroids nuclear reactions; Nucleosynthesis; Abundances. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74934/76011.pdf |
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| Mahan, Brandon; Moynier, Frederic; Siebert, Julien; Gueguen, Bleuenn; Agranier, Arnaud; Pringle, Emily A.; Bollard, Jean; Connelly, James N.; Bizzarro, Martin. |
| Chondrites and their main components, chondrules, are our guides into the evolution of the Solar System. Investigating the history of chondrules, including their volatile element history and the prevailing conditions of their formation, has implications not only for the understanding of chondrule formation and evolution but for that of larger bodies such as the terrestrial planets. Here we have determined the bulk chemical composition-rare earth, refractory, main group, and volatile element contents-of a suite of chondrules previously dated using the Pb-Pb system. The volatile element contents of chondrules increase with time from similar to 1 My after Solar System formation, likely the result of mixing with a volatile-enriched component during chondrule... |
| Tipo: Text |
Palavras-chave: Cosmochemistry; Planetary formation; Pebble accretion; Solar System evolution; Meteorites. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00638/74979/75756.pdf |
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