^1,2Mahesh Anand, ¹ Romain Tartèse,^1,2Jessica J. Barnes
¹Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
^1,2Department of Earth Sciences, The Natural History Museum, London SW7 5BD, UK

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Reference
Anand M, Tartèse R, Barnes JJ (2014) Understanding the origin and evolution of water in the Moon through lunar sample studies. Philosophical Transactions of the Royal Society A 13, 372, 2024
Link to Article [doi: 10.1098/rsta.2013.0254]

¹Sara S. Russell,²Katherine H. Joy,¹Teresa E. Jeffries, ³Guy J. Consolmagno,¹Anton Kearsley
¹Natural History Museum, Cromwell Road, London SW7 5BD, UK
²School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK
³Specola Vaticana, V-00120, Vatican City State

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Reference
Russell SS, Joy KH, Jeffries TE, Consolmagno GJ, Kearsley A (2014) Heterogeneity in lunar anorthosite meteorites: implications for the lunar magma ocean model. Philosophical Transactions of the Royal Society A 13, 372, 2024
Link to Article [doi: 10.1098/rsta.2013.0241]

¹Noronha, B. A. ^1,2Friedrich, J. M.
¹Department of Chemistry, Fordham University, Bronx, New York, USA
²Department of Earth and Planetary Sciences, American Museum of Natural History, New York, New York, USA

To establish the chemical group provenance of the five thermally altered carbonaceous chondrites Asuka (A-) 881551, Asuka-882113, Elephant Moraine (EET) 96026, Mulga (west), and Northwest Africa (NWA) 3133, we quantified 44 trace elements in each of them. We also analyzed Larkman Nunatak (LAR) 04318 (CK4), Miller Range (MIL) 090001 (CR2), Roberts Massif (RBT) 03522 (CK5) as reference samples as their chemical group affinity is already recognized. We conclude that Asuka-881551, Asuka-882113, and Mulga (west) are thermally metamorphosed CK chondrites. Compositionally, Elephant Moraine 96026 most resembles the CV chondrites. NWA 3133 is the most significantly thermally altered carbonaceous chondrite in our suite of samples. It is completely recrystallized (no chondrules or matrix remain), but its bulk composition is consistent with a CV–CK clan provenance. The thermally labile element (e.g., Se, Te, Zn, and Bi) depletion in NWA 3133 indicates a chemically open system during the heating episode. It remains unclear if the heat necessary for its thermal alteration of NWA 3133 was due to the decay of 26Al or was impact related. Finally, we infer that MIL 090001, Mulga (west), and NWA 3133 show occasional compositional signatures indicative of terrestrial alteration. The alteration is especially evident within the elements Sr, Ba, La, Ce, Th, U, and possibly Sb. Despite the alteration, we can still confidently place each of the altered chondrites within an established chemical group or clan.

Reference
Noronha BA, Friedrich JM (2014) Chemical compositions and classifica tion of five thermally altered carbonaceous chondrites. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12350]

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^1,2Gismelseed, A. M., ³Abdu, Y. A., ²Shaddad, M. H., ⁴Verma, H. C., ⁵Jenniskens, P.
¹Department of Physics, Sultan Qaboos University, Muscat, Oman
²Department of Physics, University of Khartoum, Khartoum, Sudan
³Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
⁴Department of Physics, IIT Kanpur, Kanpur, India
⁵SETI Institute, Carl Sagan Center, Mountain View, California, USA

The iron-bearing phases in a ureilite fragment (AS#051) from the Almahata Sitta meteorite are studied using Mössbauer spectroscopy, X-ray diffraction (XRD), and electron microprobe analysis (EMPA). AS#051 has a typical ureilite texture of medium- to coarse-grained silicates (olivine, orthopyroxene, and pigeonite) with minor opaques (Fe-Ni metal, troilite, and graphite). The silicate compositions, determined by EMPA, are homogeneous: olivine (Fo90.2), orthopyroxene (En86.3Fs8.6Wo5.1), and pigeonite (En81.6Fs8.9Wo9.5), and are similar to those of magnesian ureilites. The modal abundance of mineral phases was determined by Rietveld refinement of the powder XRD data. The Mössbauer spectra at 295 K and 78 K are composed of two sharp well-defined paramagnetic doublets superimposed on a well-resolved magnetic sextet and other weak absorption features. The two paramagnetic doublets are assigned to olivine and pyroxene (orthopyroxene and pigeonite), and the ferromagnetic sextet to kamacite (magnetic hyperfine field ≈ 33.2 T), in agreement with the XRD characterization. The Mössbauer results also show the presence of small amounts of troilite (FeS) and cohenite ([Fe,Ni,Co]3C). Using the Mössbauer data, the relative abundance of each Fe-bearing phase is determined and compared with the results obtained by XRD

Reference
Gismelseed AM, Abdu YA, Shaddad MH, Verma HC, Jennikens P (2014), Fe-bearing phases in a ureilite fragment from the asteroid 2008 TC3 (= Almahata Sitta meteorites): A combined Mössbauer spectroscopy and X-ray diffraction study. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12345]

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¹Trigo-Rodríguez et al. (>10)*
¹Institute of Space Sciences (CSIC-IEEC), Campus UAB, Facultat de Ciències, Bellaterra (Barcelona), Spain
*Find the extensive, full author and affiliation list on the publishers Website

We report and describe an L6 ordinary chondrite fall that occurred in Ardón, León province, Spain (longitude 5.5605°W, latitude 42.4364°N) on July 9th, 1931. The 5.5 g single stone was kept hidden for 83 yr by Rosa González Pérez, at the time an 11 yr old who had observed the fall and had recovered the meteorite. According to various newspaper reports, the event was widely observed in Northern Spain. Ardón is a very well-preserved, fresh, strongly metamorphosed (petrologic type 6), and weakly shocked (S3) ordinary chondrite with well-equilibrated and recrystallized minerals. The mineral compositions (olivine Fa23.7±0.3, low-Ca pyroxene Fs20.4±0.2Wo1.5±0.2, plagioclase An10.3±0.5Ab84.3±1.2), magnetic susceptibility (log χ = 4.95 ± 0.05 × 10−9 m3 kg−1), bulk density (3.49 ± 0.05 g cm−3), grain density (3.58 ± 0.05 g cm−3), and porosity (2.5 vol%) are typical for L6 chondrites. Short-lived radionuclides confirm that the meteorite constitutes a recent fall. The 21Ne and 38Ar cosmic ray exposure ages are both about 20–30 Ma, similar to values for many other L chondrites. The cosmogenic 22Ne/21Ne ratio indicates that preatmospheric Ardón was a relatively large body. The fact that the meteorite was hidden in private hands for 83 yr makes one wonder if other meteorite falls may have experienced the same fate, thus possibly explaining the anomalously low number of falls reported in continental Spain in the 20th century.

Reference
Trigo-Rodríguez JM (2014) The Ardón L6 ordinary chondrite: A long-hidden Spanish meteorite fall. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.1234]

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^1,2,3Li, Y.W. et al. (>10)*
¹Institut für Raumfahrtsysteme, Universität Stuttgart, Stuttgart, Germany
²School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China
³Max Plank Institut für Kernphysik, Heidelberg, Germany
*Find the extensive, full author and affiliation list on the publishers website

To understand the process of cosmic dust particle impacts and translate crater morphology on smoothed metallic surfaces to dust properties, correct calibration of the experimental impact data is needed. This article presents the results of studies of crater morphology generated by impacts using micron-sized polypyrrole (PPy)-coated olivine particles. The particles were accelerated by an electrostatic dust accelerator to high speeds before they impacted onto polished aluminum targets. The projectile diameter and velocity ranges were 0.3–1.2 μm and 3–7 km s−1. After impact, stereopair images of the craters were taken using scanning electron microscope and 3-D reconstructions made to provide diameter and depth measurements. In this study, not just the dimensions of crater diameters and depths, but also the shape and dimensions of crater lips were analyzed. The craters created by the coated olivine projectiles are shown to have complicated shapes believed to be due to the nonspherical shape of the projectiles.

Reference
Li YW et al. (2014) Morphology of craters generated by hypervelocity impacts of micron-sized polypyrrole-coated olivine particles. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12338]

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^1,4Davidson, J., ¹Krot, A. N., ¹Nagashima, K., ²Hellebrand, E., ³Lauretta, D. S.
¹Hawai‘i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, Hawai‘i, USA
²Department of Geology and Geophysics, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, Hawai‘i, USA
³Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA
⁴Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, District of Columbia, USA

We report in situ O isotope and chemical compositions of magnetite and olivine in chondrules of the carbonaceous chondrites Watson-002 (anomalous CK3) and Asuka (A)-881595 (ungrouped C3). Magnetite in Watson-002 occurs as inclusion-free subhedral grains and rounded inclusion-bearing porous grains replacing Fe,Ni-metal. In A-881595, magnetite is almost entirely inclusion-free and coexists with Ni-rich sulfide and less abundant Ni-poor metal. Oxygen isotope compositions of chondrule olivine in both meteorites plot along carbonaceous chondrite anhydrous mineral (CCAM) line with a slope of approximately 1 and show a range of Δ17O values (from approximately −3 to −6‰). One chondrule from each sample was found to contain O isotopically heterogeneous olivine, probably relict grains. Oxygen isotope compositions of magnetite in A-881595 plot along a mass-dependent fractionation line with a slope of 0.5 and show a range of Δ17O values from −2.4‰ to −1.1‰. Oxygen isotope compositions of magnetite in Watson-002 cluster near the CCAM line and a Δ17O value of −4.0‰ to −2.9‰. These observations indicate that magnetite and chondrule olivine are in O isotope disequilibrium, and, therefore, not cogenetic. We infer that magnetite in CK chondrites formed by the oxidation of pre-existing metal grains by an aqueous fluid during parent body alteration, in agreement with previous studies. The differences in Δ17O values of magnetite between Watson-002 and A-881595 can be attributed to their different thermal histories: the former experienced a higher degree of thermal metamorphism that led to the O isotope exchange between magnetite and adjacent silicates.

Reference
Davidson J, Krot AN, Nagashima K, Hellebrand E,Lauretta DS (2014) Oxygen isotope and chemical compositions of magnetite and olivine in the anomalous CK3 Watson 002 and ungrouped Asuka-881595 carbonaceous chondrites: Effects of parent body metamorphism. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12341]

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¹Yin, Q.-Z.,² Zhou, Q., ³Li, Q.-L., ³Li, X.-H., ³Liu, Y., Tang, ³G.-Q., ⁴Krot, A. N., ^5,6Jenniskens, P.
¹Department of Earth and Planetary Sciences, University of California Davis, Davis, California, USA
²Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China
³State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
⁴Hawai‘i Institute of Geophysics and Planetology, University of Hawai‘i at Manoa, Honolulu, Hawai‘i, USA
⁵SETI Institute, Mountain View, California, USA
⁶NASA Ames Research Center, Moffett Field, California, USA

Novato, a newly observed fall in the San Francisco Bay area, is a shocked and brecciated L6 ordinary chondrite containing dark and light lithologies. We have investigated the U-Pb isotope systematics of coarse Cl-apatite grains of metamorphic origin in Novato with a large geometry ion microprobe. The U-Pb systematics of Novato apatite reveals an upper intercept age of 4472 ± 31 Ma and lower intercept age of 473 ± 38 Ma. The upper intercept age is within error identical to the U-Pb apatite age of 4452 ± 21 Ma measured in the Chelyabinsk LL5 chondrite. This age is interpreted to reflect a massive collisional resetting event due to a large impact associated with the peak arrival time at the primordial asteroid belt of ejecta debris from the Moon-forming giant impact on Earth. The lower intercept age is consistent with the most precisely dated Ar-Ar ages of 470 ± 6 Ma of shocked L chondrites, and the fossil meteorites and extraterrestrial chromite relicts found in Ordovician limestones with an age of 467.3 ± 1.6 Ma in Sweden and China. The lower intercept age reflects a major disturbance related to the catastrophic disruption of the L chondrite parent body most likely associated with the Gefion asteroid family, which produced an initially intense meteorite bombardment of the Earth in Ordovician period and reset and degassed at least approximately 35% of the L chondrite falls today. We predict that the 470 Ma impact event is likely to be found on the Moon and Mars, if not Mercury.

Reference
Yin Q-Z, Zhou Q, Li Q-L, Li X-H, Liu Y, Tang G-Q, Krot AN, Jenniskens P (2014) Records of the Moon-forming impact and the 470 Ma disruption of the L chondrite parent body in the asteroid belt from U-Pb apatite ages of Novato (L6). Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12340]

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¹U. Ott et al. (>10)*
¹Faculty of Natural Sciences, Savaria University Center, University of West Hungary, Szombathely, Hungary
²Max-Planck-Institut für Chemie, Mainz, Germany
*Find the extensive, full author and affiliation list on the publishers website

Cosmogenic He, Ne, and Ar as well as the radionuclides 10Be, 26Al, 36Cl, 41Ca, 53Mn, and 60Fe have been determined on samples from the Gebel Kamil ungrouped Ni-rich iron meteorite by noble gas mass spectrometry and accelerator mass spectrometry (AMS), respectively. The meteorite is associated with the Kamil crater in southern Egypt, which is about 45 m in diameter. Samples originate from an individual large fragment (“Individual”) as well as from shrapnel. Concentrations of all cosmogenic nuclides—stable and radioactive—are lower by a factor 3–4 in the shrapnel samples than in the Individual. Assuming negligible 36Cl decay during terrestrial residence (indicated by the young crater age 85 cm, i.e., a pre-atmospheric mass >20 tons, with a preferred radius of 115–120 cm (50–60 tons). The analyzed samples came from a depth of approximately 20 cm (Individual) and approximately 50–80 cm (shrapnel). The size of the Gebel Kamil meteoroid determined in this work is close to estimates based on impact cratering models combined with expectations for ablation during passage through the atmosphere (Folco et al. 2010, 2011).

Reference
Ott U et al. (2014) Cosmic ray exposure and pre-atmospheric size of the Gebel Kamil iron Meteorite. Meteoritics & Planetary Science (in Press).
Link to Article [DOI: 10.1111/maps.12334]

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¹Richard J. Walker
¹Isotope Geochemistry Laboratory, Department of Geology, University of Maryland, College Park, MD 20742, USA

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Reference
Walker RJ (2014)Siderophile element constraints on the origin of the Moon. Philosophical Transactions of the Royal Society A 13, 372, 2024
Link to Article [doi: 10.1098/rsta.2013.0258]