¹M.A.Barucci et al. (>10)
Astronomy & Astrophysics 629 A13 Link to Article [https://doi.org/10.1051/0004-6361/201935851]
¹LESIA, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Sorbonne Paris Cité, UPMC Université Paris 06, Sorbonne Universités, 5 place Jules Janssen, 92195 Meudon, France

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^1,2Wei Wu,^1,2Yi-Gang Xu,¹Zhao-Feng Zhang,¹Xin Li
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2019.12.001]
¹State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
²School of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing 100049, China
Copyright Elsevier

Calcium isotopes have the potential to explore genetic links between the Moon and Earth. Here, we constrain calcium isotopic composition of the bulk silicate Moon (BSM), using petrological, geochemical and calcium isotopic data obtained from five lunar meteorites (two basalts and three feldspathic breccia rocks), and on four anorthite crystals from two feldspathic breccia meteorites. The δ^44/40Ca of lunar feldspathic breccias are 0.76 ± 0.06‰ (2SD, n=3), 0.78 ± 0.10‰ (2SD, n=6) and 0.82 ± 0.02‰ (2SD, n=3), respectively, consistent with previously determined calcium isotopic composition of feldspathic breccias. Four anorthite crystals yield a mean δ^44/40Ca value of 0.75 ± 0.13‰ (2SD, n=4), inferred to represent the δ^44/40Ca value of the lunar crust. The δ^44/40Ca values of the two lunar basalts are 0.90 ± 0.07‰ (2SD,n=3) and 0.96 ± 0.11‰ (2SD, n=4), respectively, slightly heavier than the feldspathic breccias and anorthites. The δ^44/40Ca of the studied lunar basalts and literature data show negative correlations with CaO, Al₂O₃, and anorthite mode, pointing to the effect of contamination by lunar crust rocks. Using the heaviest δ^44/40Ca found in the least contaminated lunar basalts and a 0.10–0.20‰ fractionation of calcium isotopes during partial melting, we estimate the δ^44/40Ca value of the lunar mantle to be 0.96-1.11‰. The δ^44/40Ca values of the BSM is estimated to be 0.89-0.95‰, using a two-end member mixing model. The Ca isotopic composition of the BSM is within error to that of the bulk silicate Earth (0.94 ± 0.05‰), providing insights into the information of the comparison of the Earth-Moon system and the planets of inner Solar System.

¹Hans-Peter Gail,²Mario Trieloff
Astronomy & Astrophysics 628, A77 Link to Article [https://doi.org/10.1051/0004-6361/201936020]
¹Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany
²Klaus-Tschira-Labor für Kosmochemie, Institut für Geowissenschaften, Universität Heidelberg, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany

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¹F. Comerón,²B. Merín,³B. Reipurth,¹H.-W. Yen
Astronomy & Astrophysics 628, A97 Link to Article
[https://doi.org/10.1051/0004-6361/201834743]
¹European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
²European Space Astronomy Centre (ESAC), European Space Agency (ESA), 28691 Villanueva de la Cañada, Spain
³Institute for Astronomy, University of Hawaii at Manoa, 640 N. Aohoku Place, Hilo, HI 96720, USA

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¹S. Massalkhi,¹M. Agúndez,¹J. Cernicharo
Astronomy & Astrophysics 628, A62 Link to Article
[https://doi.org/10.1051/0004-6361/201935069]
¹Instituto de Física Fundamental, CSIC, C/Serrano 123, 28006 Madrid, Spain

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¹M. Bhatt,²C. Wöhler,²A. Grumpe,^3,4N. Hasebe,^4,5M. Naito
Astronomy & Astrophysics 627, A155 Link to Article
[https://doi.org/10.1051/0004-6361/201935773]
¹Physical Research Laboratory, Ahmedabad 380009, India
²Image Analysis Group, Dortmund University of Technology, Otto-Hahn Str. 4, 44227 Dortmund, Germany
³School of Advanced Science and Engineering, Waseda University, Tokyo 1698555, Japan
⁴Research Institute for Science and Engineering, Waseda University, Tokyo 1698555, Japan
⁵National Institute for Quantum and Radiological Science and Technology (QST), Chiba 2638555, Japan

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¹B. Augé,²E. Dartois,¹J. Duprat,¹C. Engrand,¹G. Slodzian,³T. D. Wu,³J. L. Guerquin-Kern,⁴H. Vermesse,⁵A. N. Agnihotri,⁵P. Boduch,⁵H. Rothard
Astronomy & Astrophysics 627, A122 Link to Article [https://doi.org/10.1051/0004-6361/201935143]
¹Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris Sud, UMR 8609-CNRS/IN2P3, 91405 Orsay, France
²Institut des Sciences Moléculaires d’Orsay (ISMO), Université Paris Sud, UMR 8609-CNRS/IN2P3, 91405 Orsay, France
³Institut Curie, PSL Research University, INSERM, U1196, 91405 Orsay, France
⁴IFP Energies Nouvelles, direction Géosciences, 92500 Rueil-Malmaison, France
⁵Centre de Recherche sur les Ions, les Matériaux et la Photonique (CIMAP) CEA/CNRS/ENSICAEN/Université de Caen Normandie, Boulevard Henri Becquerel, BP 5133 14070 Caen Cedex 05, France

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¹Michael W.Broadley,¹David V.Bekaert,¹ Bernard Marty,²Akira Yamaguchi,³Jean-Alix Barrat
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2019.11.032]
¹Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS—Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, F-54501 Vandoeuvre-lès-Nancy, France
²National Institute of Polar Research, Tachikawa, Tokyo 190-8518, Japan
³Laboratoire Geoscience Océan, UMR 6538 CNRS—Université de Bretagne Occidentale et Institut Universitaire Européen de la Mer, Place Nicolas Copernic, 29280 Plouzané, France
Copyright Elsevier

Ureilites are equilibrated carbon-rich olivine-pyroxene rocks from the partially melted mantle of a large (>500 km diameter) heterogeneous parent body. Recently the ureilite parent body was interpreted as an incomplete mixture of material from two carbon-rich chondritic reservoirs, one (Mg-rich) with reduced iron, low Δ¹⁷O and low δ¹³C, and the other with oxidised iron, high Δ¹⁷O and high δ¹³C. Here we analyse noble gases (Ar, Kr and Xe) in six equilibrated (unbrecciated) ureilites from Northwest Africa (NWA 2236, NWA 7686, NWA 8049, NWA 8172, NWA 11032 and NWA 11368). We observe weak positive and negative correlations of Δ¹⁷O and Mg# with the elemental ratios of Ar/Xe and Kr/Xe, respectively, as well as a weak positive correlation of Mg# with the heavy isotopes of Xe. These correlations broadly support the idea of the two-component mixing hypothesis. Our analyses further suggest that the Mg-rich endmember was rich in Xe from presolar grains (HL-Xe) while the Mg-poorer component may have contained solar-derived noble gases. The observed correlations are less straightforward to reconcile with a recent model for the origin of the ureilite parent body, involving oxidation of metal by H₂O from accreted ice with ‘heavy’ oxygen isotopes.

¹Ryan C.Ogliore,²Russell L.Palma,³ Julien Stodolna,⁴Kazuhide Nagashima,⁵Robert O.Pepin,⁵ D.J.Schlutter,⁶Zack Gainsforth,⁶Andrew J.Westphal,⁴Gary R.Huss
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2019.11.033]
¹Department of Physics, Washington University in St. Louis, St. Louis, MO 63130
²Minnesota State University – Mankato
³EDF Lab les Renardiéres 77818 Moret Sur Loing France
⁴Hawai‘i Institute of Geophysics and Planetology, University of Hawai‘i at Mānoa, Honolulu, HI 96822
⁵University of Minnesota – Twin Cities
⁶Space Sciences Laboratory, University of California at Berkeley
Copyright Elsevier

We report the structure, chemical composition, O, Al-Mg, He, and Ne isotope systematics of an interplanetary dust particle, “Manchanito”. These analyses indicate that Manchanito solidified as refractory glass (with oxidized Fe but reduced Ti) in a chondrule-like formation environment more than 3.2 Myr after CAIs, after which it was exposed to Q-like noble gases in the dissipating solar nebula. Manchanito’s He and Ne isotopic composition and concentrations are similar to those measured in samples of comet Wild 2, from which we infer that Manchanito’s parent body was a comet. We propose that after formation and exposure to Q-like gases, Manchanito was transported to the outer Solar System where it came into contact with organics and volatile ices on its cometary parent body. Manchanito provides additional evidence that cometary solids have been subjected to energetic processing and large-scale transport in a wide range of environments in the Solar System.

¹A. P. Jones,¹N. Ysard
Astronomy & Astrophysics 627, A38 Link to Article [https://doi.org/10.1051/0004-6361/201935532]
¹Astrophysique Spatiale, CNRS/Université Paris-Sud, Université Paris-Saclay, Bâtiment 121, Université Paris-Sud, 91405 Orsay Cedex, France

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