^1,2Luke Daly, ²Phil A. Bland, ³David W. Saxey, ^2,3Steven M. Reddy, ^2,3Denis Fougerouse, ³William D.A. Rickard, ²Lucy V. Forman
Geology 45, 847-850 Link to Article [DOI: https://doi.org/10.1130/G39075.1]
¹School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
²Department of Applied Geology, Curtin University, GPO Box U1987, Perth, WA 6102, Australia
³Geoscience Atom Probe Facility, Advanced Resource Characterisation Facility, John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA 6845, Australia

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^1,2Birger Schmitz, ²Philipp R. Heck, ^3,4Walter Alvarez, ⁵Noriko T. Kita, ²Surya S. Rout,⁶Anders Cronholm, ⁵Céline Defouilloy, ⁶Ellinor Martin, ^7,8Jan Smit, ⁶Fredrik Terfelt
Geology 45, 807-810 Link to Article [DOI: https://doi.org/10.1130/G39297.1]
¹Astrogeobiology Laboratory, Department of Physics, Lund University, SE-22100 Lund, Sweden
²Robert A. Pritzker Center for Meteoritics and Polar Studies, The Field Museum of Natural History, Chicago, Illinois 60605, USA
³Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
⁴Osservatorio Geologico di Coldigioco, Contrada Coldigioco 4, 62021 Apiro, Italy
⁵WiscSIMS, Department of Geoscience, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
⁶Astrogeobiology Laboratory, Department of Physics, Lund University, SE-22100 Lund, Sweden
⁷Osservatorio Geologico di Coldigioco, Contrada Coldigioco 4, 62021 Apiro, Italy
⁸Department of Sedimentary Geology, Vrije Universiteit, 1081 HV Amsterdam, Netherlands

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^1,2,3Wang Hao, ^1,2Ma Yue-hua,^1,2,4Zhao Hai-bin, ^4,5LuXiao-ping
Chinese Astronomy and Astrophysics 41,419-429 Link to Article [https://doi.org/10.1016/j.chinastron.2017.08.009]
¹Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008
²Key Laboratory of Planetary Sciences, Chinese Academy of Sciences, Nanjing 210008
³University of Chinese Academy of Sciences, Bejing 100049
⁴Partner Laboratory of The Lunar and Planetary Science Laboratory, Macau University of Science and Technology and The Key Laboratory of Lunar and Deep Space Exploration, Chinese Academy of Sciences, Macau 000853
⁵Faculty of Information Technology, Macau University of Science and Technology, Macau 000853

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¹V. Moggi Cecchi, ²G. Pratesi, ³S. Caporali, ⁴C. D. K. Herd, ⁴G. Chen
The european Physics Journal Plus 132, 359 Link to Article [https://doi.org/10.1140/epjp/i2017-11640-4]
¹Museo di Storia Naturale Università degli Studi di Firenze Firenze Italy
²Dipartimento di Scienze della Terra Università degli Studi di Firenze Firenze Italy
³Dipartimento di Ingegneria Industriale Università degli Studi di Firenze Firenze Italy
⁴Department of Earth and Atmospheric Sciences University of Alberta Edmonton Canada

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¹Shaunna M. Morrison et al. (>10)
American Mineralogist 102, 1588-1596 Link to Article [DOI
https://doi.org/10.2138/am-2017-6104CCBYNCND]
¹Geophysical Laboratory, Carnegie Institution for Science, 5251 Broad Branch Road NW, Washington, D.C. 20015, U.S.A.
Copyright: The Mineralogical Society of America

A fundamental goal of mineralogy and petrology is the deep understanding of mineral phase relationships and the consequent spatial and temporal patterns of mineral coexistence in rocks, ore bodies, sediments, meteorites, and other natural polycrystalline materials. The multi-dimensional chemical complexity of such mineral assemblages has traditionally led to experimental and theoretical consideration of 2-, 3-, or n-component systems that represent simplified approximations of natural systems. Network analysis provides a dynamic, quantitative, and predictive visualization framework for employing “big data” to explore complex and otherwise hidden higher-dimensional patterns of diversity and distribution in such mineral systems. We introduce and explore applications of mineral network analysis, in which mineral species are represented by nodes, while coexistence of minerals is indicated by lines between nodes. This approach provides a dynamic visualization platform for higher-dimensional analysis of phase relationships, because topologies of equilibrium phase assemblages and pathways of mineral reaction series are embedded within the networks. Mineral networks also facilitate quantitative comparison of lithologies from different planets and moons, the analysis of coexistence patterns simultaneously among hundreds of mineral species and their localities, the exploration of varied paragenetic modes of mineral groups, and investigation of changing patterns of mineral occurrence through deep time. Mineral network analysis, furthermore, represents an effective visual approach to teaching and learning in mineralogy and petrology.

¹Emmanuel Jacquet,²Yves Marrocchi
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12985]
¹Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS & Muséum National d’Histoire Naturelle, UMR 7590, Paris, France
²Centre de Recherches Pétrographiques et Géochimiques, CNRS, Université de Lorraine, UMR 7358, Vandoeuvre-lès-Nancy, France
Published by arrangement with John Wiley & Sons

We report combined oxygen isotope and mineral-scale trace element analyses of amoeboid olivine aggregates (AOA) and chondrules in ungrouped carbonaceous chondrite, Northwest Africa 5958. The trace element geochemistry of olivine in AOA, for the first time measured by LA-ICP-MS, is consistent with a condensation origin, although the shallow slope of its rare earth element (REE) pattern is yet to be physically explained. Ferromagnesian silicates in type I chondrules resemble those in other carbonaceous chondrites both geochemically and isotopically, and we find a correlation between 16O enrichment and many incompatible elements in olivine. The variation in incompatible element concentrations may relate to varying amounts of olivine crystallization during a subisothermal stage of chondrule-forming events, the duration of which may be anticorrelated with the local solid/gas ratio if this was the determinant of oxygen isotopic ratios as proposed recently. While aqueous alteration has depleted many chondrule mesostases in REE, some chondrules show recognizable subdued group II-like patterns supporting the idea that the immediate precursors of chondrules were nebular condensates.

¹Yukako Kato,^1,2Toshimori Sekine,^1,3Masahiko Kayama,^1,4Masaaki Miyahara,^5,6Akira Yamaguchi
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12957]
¹Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
²Center for High Pressure Science and Technology Advanced Research, Shanghai, China
³Creative Interdisciplinary Research Division, Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
⁴Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, Sendai, Japan
⁵National Institute of Polar Research, Tokyo, Japan
⁶Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate University for Advanced Studies), Tokyo, Japan
Published by arrangement with John Wiley & Sons

Shock pressure recorded in Yamato (Y)-790729, classified as L6 type ordinary chondrite, was evaluated based on high-pressure polymorph assemblages and cathodoluminescence (CL) spectra of maskelynite. The host-rock of Y-790729 consists mainly of olivine, low-Ca pyroxene, plagioclase, metallic Fe-Ni, and iron-sulfide with minor amounts of phosphate and chromite. A shock-melt vein was observed in the hostrock. Ringwoodite, majorite, akimotoite, lingunite, tuite, and xieite occurred in and around the shock-melt vein. The shock pressure in the shock-melt vein is about 14–23 GPa based on the phase equilibrium diagrams of high-pressure polymorphs. Some plagioclase portions in the host-rock occurred as maskelynite. Sixteen different CL spectra of maskelynite portions were deconvolved using three assigned emission components (centered at 2.95, 3.26, and 3.88 eV). The intensity of emission component at 2.95 eV was selected as a calibrated barometer to estimate shock pressure, and the results indicate pressures of about 11–19 GPa. The difference in pressure between the shock-melt vein and host-rock might suggest heterogeneous shock conditions. Assuming an average shock pressure of 18 GPa, the impact velocity of the parent-body of Y-790729 is calculated to be ~1.90 km s⁻¹. The parent-body would be at least ~10 km in size based on the incoherent formation mechanism of ringwoodite in Y-790729.

¹A.Yelisseyev, ²V.Vins, ¹V.Afanasiev, ³A.Rybak
Diamonds and Related Materials 79, 7-13 Link to Article [https://doi.org/10.1016/j.diamond.2017.08.012]
¹Sobolev Institute of Geology and Mineralogy, Russian Academy of Sciences, Siberian Branch, 3 Academician Koptyug Ave., Novosibirsk 630090, Russia
²VELMAN Ltd, 1/3 Zelenaya Gorka Str., Novosibirsk 630060, Russia
³Novosibirsk State Technical University, 20 K. Marx Ave., Novosibirsk 630073, Russia

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^1,2,3Debra H. Needham, ^1,2David A. Kring
Earth and Planetary Science Letters (in Press) Link to Article [https://doi.org/10.1016/j.epsl.2017.09.002]
¹Center for Lunar Science and Exploration, Lunar and Planetary Institute, Houston, TX, United States
²NASA Solar System Exploration Virtual Institute
³NASA Marshall Space Flight Center, Huntsville, AL, United States
Copyright Elsevier

Studies of the lunar atmosphere have shown it to be a stable, low-density surface boundary exosphere for the last 3 billion years. However, substantial volcanic activity on the Moon prior to 3 Ga may have released sufficient volatiles to form a transient, more prominent atmosphere. Here, we calculate the volume of mare basalt emplaced as a function of time, then estimate the corresponding production of volatiles released during the mare basalt-forming eruptions. Results indicate that during peak mare emplacement and volatile release ∼3.5 Ga, the maximum atmospheric pressure at the lunar surface could have reached ∼1 kPa, or ∼1.5 times higher than Mars’ current atmospheric surface pressure. This lunar atmosphere may have taken ∼70 million years to fully dissipate. Most of the volatiles released by mare basalts would have been lost to space, but some may have been sequestered in permanently shadowed regions on the lunar surface. If only 0.1% of the mare water vented during these eruptions remains in the polar regions of the Moon, volcanically-derived volatiles could account for all hydrogen deposits – suspected to be water – currently observed in the Moon’s permanently shadowed regions. Future missions to such locations may encounter evidence of not only asteroidal, cometary, and solar wind-derived volatiles, but also volatiles vented from the interior of the Moon.

^1,2Martin D.Suttle, ^1,2Matthew J.Genge
Earth and Planetary Science Letters (in Press) Link to Article [https://doi.org/10.1016/j.epsl.2017.07.052]
¹Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
²Department of Earth Science, The Natural History Museum, Cromwell Rd, London SW7 5BD, UK
Copyright Elsevier

We report the discovery of fossil micrometeorites from Late Cretaceous chalk. Seventy-six cosmic spherules were recovered from Coniacian (87±1 Ma) sediments of the White Chalk Supergroup. Particles vary from pristine silicate and iron-type spherules to pseudomorphic spherules consisting of either single-phase recrystallized magnetite or Fe-silicide. Pristine spherules are readily identified as micrometeorites on the basis of their characteristic mineralogies, textures and compositions. Both magnetite and silicide spherules contain dendritic crystals and spherical morphologies, testifying to rapid crystallisation of high temperature iron-rich metallic and oxide liquids. These particles also contain spherical cavities, representing weathering and removal of metal beads and irregular cavities, representing vesicles formed by trapped gas during crystallization; both features commonly found among modern Antarctic Iron-type (I-type) cosmic spherules. On the basis of textural analysis, the magnetite and Fe-silicide spherules are shown to be I-type cosmic spherules that have experienced complete secondary replacement during diagenesis (fossilization). Our results demonstrate that micrometeorites, preserved in sedimentary rocks, are affected by a suite of complex diagenetic processes, which can result in disparate replacement minerals, even within the same sequence of sedimentary beds. As a result, the identification of fossil micrometeorites requires careful observation of particle textures and comparisons with modern Antarctic collections. Replaced micrometeorites imply that geochemical signatures the extraterrestrial dust are subject to diagenetic remobilisation that limits their stratigraphic resolution. However, this study demonstrates that fossil, pseudomorphic micrometeorites can be recognised and are likely common within the geological record.