¹John F. Mustard
Journal of Geophysical Research Planets (in Press) Link to Article [DOI: 10.1002/2017JE005315]
¹Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, USA
Published by arrangement with John Wiley & Sons

Remotely sensed data and the instruments that acquire them are core parts of Earth and planetary observation systems. They are used to quantify the Earth’s interconnected systems, and remote sensing is the only way to get a daily, or more frequent, snapshot of the status of the Earth. It really is the Earth’s stethoscope. In a similar manner remote sensing is the rock hammer of the planetary scientist and the only way comprehensive data sets can be acquired. To risk offending many remotely sensed data acquired across the electromagnetic spectrum, it is the tricorder to explore known and unknown planets. Arriving where we are today in the use of remotely sensed data in the solar system has been a continually evolving synergy between Earth observation, planetary exploration, and fundamental laboratory work.

¹V.Payré et al. (>10)*
Journal of Geophysical Research Planets (in Press) Link to Article [DOI: 10.1002/2016JE005201]
¹GeoRessources, Université de Lorraine, Nancy, France
*Find the extensive, full author and affiliation list on the publishers website
Published by arrangement with John Wiley & Sons

The Chemistry Camera (ChemCam) instrument onboard Curiosity can detect minor and trace elements such as lithium, strontium, rubidium, and barium. Their abundances can provide some insights about Mars’ magmatic history and sedimentary processes. We focus on developing new quantitative models for these elements by using a new laboratory database (more than 400 samples) that displays diverse compositions that are more relevant for Gale crater than the previous ChemCam database. These models are based on univariate calibration curves. For each element, the best model is selected depending on the results obtained by using the ChemCam calibration targets onboard Curiosity. New quantifications of Li, Sr, Rb, and Ba in Gale samples have been obtained for the first 1000 Martian days. Comparing these data in alkaline and magnesian rocks with the felsic and mafic clasts from the Martian meteorite NWA7533—from approximately the same geologic period—we observe a similar behavior: Sr, Rb, and Ba are more concentrated in soluble- and incompatible-element-rich mineral phases (Si, Al, and alkali-rich). Correlations between these trace elements and potassium in materials analyzed by ChemCam reveal a strong affinity with K-bearing phases such as feldspars, K-phyllosilicates, and potentially micas in igneous and sedimentary rocks. However, lithium is found in comparable abundances in alkali-rich and magnesium-rich Gale rocks. This very soluble element can be associated with both alkali and Mg-Fe phases such as pyroxene and feldspar. These observations of Li, Sr, Rb, and Ba mineralogical associations highlight their substitution with potassium and their incompatibility in magmatic melts.

^1,2Surya S. Rout,^1,2,3Philipp R. Heck,⁴Nestor J. Zaluzec,⁵Takayuki Ishii,⁶Jianguo Wen,⁶Dean J. Miller,^1,7Birger Schmitz
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12887]
¹Robert A. Pritzker Center for Meteoritics and Polar Studies, The Field Museum of Natural History, Chicago, Illinois, USA
²Chicago Center for Cosmochemistry, The University of Chicago, Chicago, Illinois, USA
³Department of the Geophysical Sciences, The University of Chicago, Chicago, Illinois, USA
⁴Photon Science Division, Argonne National Laboratory, Argonne, Illinois, USA
⁵Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
⁶Electron and X-ray Microscopy, Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois, USA
⁷Astrogeobiology Laboratory, Department of Physics, Lund University, SE, Lund, Sweden
Published by arrangement with John Wiley & Sons

Chromites from Middle Ordovician fossil L chondrites and from matrix and shock-melt veins in Catherwood, Tenham, and Coorara L chondrites were studied using Raman spectroscopy and TEM. Raman spectra of chromites from fossil L chondrites showed similarities with chromites from matrix and shock-melt veins in the studied L chondrite falls and finds. Chromites from shock-melt veins of L chondrites show polycrystallinity, while the chromite grains in fossil L chondrites are single crystals. In addition, chromites from shock-melt veins in the studied L chondrites have high densities of planar fractures within the subgrains and many subgrains show intergrowths of chromite and xieite. Matrix chromite of Tenham has similar dislocation densities and planar fractures as a chromite from the fossil meteorite Golvsten 001 and higher dislocation densities than in chromite from the fossil meteorite Sextummen 003. Using this observation and knowing that the matrix of Tenham experienced 20–22 GPa and <1000° C, an upper limit for the P,T conditions of chromite from Golvsten 001 and Sextummen 003 can be estimated to be 20–22 GPa and 1000° C (shock stage S3–S6) and 20 GPa and 1000° C (S3–S5), respectively, and we conclude that the studied fossil meteorite chromites are from matrix.

^1,2Tuan H. Vu, ^1,2Robert Hodyss, ^1,2Paul V. Johnson, ^1,2Mathieu Choukroun
Planetary and Space Science (in Press) Link to Article [https://doi.org/10.1016/j.pss.2017.04.014]
¹Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
²NASA Astrobiology Institute

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Selby Cull-Hearth, ¹M. Caroline Clark
Planetary and Space Science (in Press) Link to Article [https://doi.org/10.1016/j.pss.2017.03.011]
¹Bryn Mawr College, Bryn Mawr, PA, USA 19010

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Jack Wisdom
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12876]
¹Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Published by arrangement with John Wiley & Sons

Meteorites are delivered from the asteroid belt by way of chaotic zones (Wisdom 1985a). The dominant sources are believed to be the chaotic zones associated with the ν6 secular resonance, the 3:1 mean motion resonance, and the 5:2 mean motion resonance. Though the meteorite transport process has been previously studied, those studies have limitations. Here I reassess the meteorite transport process with fewer limitations. Prior studies have not been able to reproduce the afternoon excess (the fact that approximately twice as many meteorites fall in the afternoon as in the morning) and suggested that the afternoon excess is an observational artifact; here it is shown that the afternoon excess is in fact consistent with the transport of meteorites by way of chaotic zones in the asteroid belt. By studying models with and without the inner planets it is found that the inner planets significantly speed up the transport of meteorites.

^1,2Vesselin Dekov, ³Pierre Rochette, ³Jérôme Gattacceca
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12879]
¹Tokyo University of Marine Science and Technology, Tokyo, Japan
²Department of Marine Geosciences, IFREMER, Centre de Brest, Plouzané, France
³Aix-Marseille Univ, CNRS, IRD, Coll France, CEREGE, Aix-en-Provence, France
Published by arrangement with John Wiley & Sons

We present a summary of the mineralogy, mineral chemistry, and magnetic characteristics of all the five Bulgarian meteorite falls. We report the first mineralogical descriptions, chemical analyses, and magnetic measurements of the Konevo (1931) and Silistra (1917) meteorites. We classify Konevo as LL5, and Silistra as an ungrouped achondrite with HED affinities. Pavel (1966; previously classified as an H5) is reclassified as H3-anomalous. We also provide precise mineralogy and mineral chemistry of the Virba meteorite (1873, L6), and more details on the mineral chemistry of Gumoschnik (1904, H5).

¹Shigeko Togashi, ²Noriko T. Kita, ¹Akihiko Tomiya, ^1,3Yuichi Morishita
Geochimica et Cosmochimica Acta (in Press) Link to Article [http://doi.org/10.1016/j.gca.2017.04.031]
¹Geological Survey of Japan, AIST, Central 7, Higashi 1-1-1, Tsukuba 305-8567, Japan
²Department of Geoscience, University of Wisconsin-Madison, 1215 W Dayton Street Madison, WI 53706-1692, USA
³Department of Geoscience, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
Copyright Elsevier

The compositions of host magmas of ferroan anorthosites (FAN-host magmas) were estimated from secondary ion mass spectrometry analyses of plagioclase in lunar highland rocks. The evolution of the magmas was investigated by considering phase relations based on the MELTS algorithm and by re-examining partition coefficients for trace elements between plagioclase and melts. Data little affected by post-magmatic processes were selected by using plagioclase with relatively primitive Sc and Co contents. The FAN-host magma contained 90–174 ppm Sr, 40–119 ppm Ba and 0.5–1.3% TiO2, and had sub-chondritic Sr/Ba and Ti/Ba ratios. It is difficult to account for the formation of FAN-host magma on the basis of magma evolution processes of previously proposed bulk silicate Moon models with chondritic ratios for refractory elements at global scale. Therefore, the source of the FAN-host magma must have had primordial sub-chondritic Sr/Ba and Ti/Ba ratios. The FAN-host magmas were consistent in refractory elements with the estimated host mafic magma for feldspathic crust based on lunar meteorites, and some very-low-Ti mare rocks from lunar meteorites. Here, we propose an alternative bulk silicate Moon model (the cBSM model), which is enriched in crustal components of proto-bodies relative to the present whole Earth–Moon system.

^1,2Lukáš Ackerman, ²Tomáš Magna, ¹Karel Žák, ¹Roman Skála, ¹Šárka Jonášová, ³Jiří Mizera, ³Zdeněk Řanda
Geochimica et Cosmochimica Acta (in Press) Link to Article [http://doi.org/10.1016/j.gca.2017.04.028]
¹Institute of Geology, The Czech Academy of Sciences, Rozvojová 269, CZ-165 00 Prague 6 – Lysolaje, Czech Republic
²Czech Geological Survey, Klárov 3, CZ-118 21 Prague 1, Czech Republic
³Nuclear Physics Institute, The Czech Academy of Sciences, Hlavní 130, CZ-250 68 Husinec-Řež, Czech Republic
Copyright Elsevier

Impact processes are natural phenomena that contribute to a variety of physico–chemical mechanisms over an extreme range of shock pressures and temperatures, otherwise seldomly achieved in the Earth’s crust through other processes. Under these extreme conditions with transient temperatures and pressures ≥3,000K and ≥100 GPa, followed by their rapid decrease, the behavior of elements has remained poorly understood. Distal glassy ejecta (tektites) were produced in early phases of contact between the Earth’s surface and an impacting body. Here we provide evidence for a complex behavior of Os and other highly siderophile elements (HSE; Ir, Ru, Pt, Pd, and Re) during tektite production related to a hyper-velocity impact that formed the Ries structure in Germany. Instead of simple mixing between the surface materials, which are thought to form the major source of central European tektites (moldavites), and impactor matter, the patterns of HSE contents and 187Re/188Os – 187Os/188Os ratios in moldavites, target sediments and impact-related breccias (suevites) can be explained by several sequential and/or contemporary processes. These involve (i) evaporative loss of partially oxidized HSE from the overheated tektite melt, (ii) mixing of target-derived and impactor-derived HSE vapor (plasma) phases, and (iii) early (high-temperature) condensation of a part of the mixed vapor phase back to silicate melt droplets. An almost complete loss of terrestrial Os from the tektite melt and its replacement with extra-terrestrial Os are indicated by low 187Os/188Os ratios in tektites (<0.163) relative to precursor materials (>0.69). This is paralleled by a co-variation between Os and Ni contents in tektites but not in suevites formed later in the impact process.

^1,2,3Levke Kööp, ^4,5Daisuke Nakashima, ^1,2,3Philipp R. Heck, ⁴Noriko T. Kita, ^4,6Travis J. Tenner, ⁷Alexander N. Krot, ⁷Kazuhide Nagashima, ^7,8Changkun Park, ^1,2,3,9Andrew M. Davis
Geochimica et Cosmochimica Acta (in Press) Link to Article [http://doi.org/10.1016/j.gca.2017.04.029]
¹Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637, USA
²Chicago Center for Cosmochemistry, The University of Chicago, Chicago, IL 60637, USA
³Robert A. Pritzker Center for Meteoritics and Polar Studies, Field Museum of Natural History, Chicago, IL, USA
⁴Department of Geoscience, University of Wisconsin, Madison, WI 53706, USA
⁵Division of Earth and Planetary Material Sciences, Faculty of Science, Tohoku University, Aoba, Sendai, Miyagi 980-8578, Japan
⁶Chemistry Division, Nuclear and Radiochemistry, Los Alamos National Laboratory, MSJ514, Los Alamos, NM 87545, USA
⁷Hawai‘i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, HI
⁸Korea Polar Research Institute, Incheon 21990, Korea
⁹Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637, USA.
Copyright Elsevier

Calcium-aluminum-rich inclusions (CAIs) are the oldest dated objects that formed inside the Solar System. Among these are rare, enigmatic objects with large mass-dependent fractionation effects (F CAIs), which sometimes also have large nucleosynthetic anomalies and a low initial abundance of the short-lived radionuclide 26Al (FUN CAIs). We have studied seven refractory hibonite-rich CAIs and one grossite-rich CAI from the Murchison (CM2) meteorite for their oxygen, calcium, and titanium isotopic compositions. The 26Al-26Mg system was also studied in seven of these CAIs. We found mass-dependent heavy isotope enrichment in all measured elements, but never simultaneously in the same CAI. The data are hard to reconcile with a single-stage melt evaporation origin and may require isotopic reintroduction or reequilibration for magnesium, oxygen and titanium after evaporation for some of the studied CAIs.

The initial 26Al/27Al ratios inferred from model isochrons span a range from <1×10–6 to canonical (∼5×10–5). The CAIs show a mutual exclusivity relationship between inferred incorporation of live 26Al and the presence of resolvable anomalies in 48Ca and 50Ti. Furthermore, a relationship exists between 26Al incorporation and Δ17O in the hibonite-rich CAIs (i.e., 26Al-free CAIs have resolved variations in Δ17O, while CAIs with resolved 26Mg excesses have Δ17O values close to –23‰). Only the grossite-rich CAI has a relatively enhanced Δ17O value (∼–17‰) in spite of a near-canonical 26Al/27Al. We interpret these data as indicating that fractionated hibonite-rich CAIs formed over an extended time period and sampled multiple stages in the isotopic evolution of the solar nebula, including: (1) an 26Al-poor nebula with large positive and negative anomalies in 48Ca and 50Ti and variable Δ17O; (2) a stage of 26Al-admixture, during which anomalies in 48Ca and 50Ti had been largely diluted and a Δ17O value of ∼ –23‰ had been achieved in the CAI formation region; and (3) a nebula with an approximately canonical level of 26Al and a Δ17O value of ∼ –23‰ in the CAI formation region.