^1,2José M. Madiedo et al. (>10 Authors)*
¹Departamento de Física Atómica, Molecular y Nuclear, Facultad de Física, Universidad de Sevilla, 41012 Sevilla, Spain
²Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva, Spain
*Find the extensive, full author and affiliation list on the publishers website

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Reference
José M. Madiedo et al. (2014) Trajectory, orbit, and spectroscopic analysis of a bright fireball observed over Spain on April 13, 2013. Astronomy&Astrophysics 569 (in Press)
Link to Article [http://www.aanda.org/articles/aa/abs/2014/09/aa22120-13/aa22120-13.html]

^1,2Yoko Kebukawa,³Michael E. Zolensky,⁴A. L. David Kilcoyne,⁵Zia Rahman,^6,7Peter Jenniskens,¹George D. Cody
¹Geophysical Laboratory, Carnegie Institution of Washington, Washington, District of Columbia, USA
²Department of Natural History Sciences, Hokkaido University, Sapporo, Japan
³NASA Johnson Space Center, Houston, Texas, USA
⁴Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁵Jacobs-Sverdrup, Houston, Texas, USA
⁶SETI Institute, Mountain View, California, USA
⁷NASA Ames Research Center, Moffett Field, California, USA

The Sutter’s Mill (SM) meteorite fell in El Dorado County, California, on April 22, 2012. This meteorite is a regolith breccia composed of CM chondrite material and at least one xenolithic phase: oldhamite. The meteorite studied here, SM2 (subsample 5), was one of three meteorites collected before it rained extensively on the debris site, thus preserving the original asteroid regolith mineralogy. Two relatively large (10 μm sized) possible diamond grains were observed in SM2-5 surrounded by fine-grained matrix. In the present work, we analyzed a focused ion beam (FIB) milled thin section that transected a region containing these two potential diamond grains as well as the surrounding fine-grained matrix employing carbon and nitrogen X-ray absorption near-edge structure (C-XANES and N-XANES) spectroscopy using a scanning transmission X-ray microscope (STXM) (Beamline 5.3.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory). The STXM analysis revealed that the matrix of SM2-5 contains C-rich grains, possibly organic nanoglobules. A single carbonate grain was also detected. The C-XANES spectrum of the matrix is similar to that of insoluble organic matter (IOM) found in other CM chondrites. However, no significant nitrogen-bearing functional groups were observed with N-XANES. One of the possible diamond grains contains a Ca-bearing inclusion that is not carbonate. C-XANES features of the diamond-edges suggest that the diamond might have formed by the CVD process, or in a high-temperature and -pressure environment in the interior of a much larger parent body.

Reference
Kebukawa Y, Zolensky ME, Kilcoyne ALD, Rahman Z, Jenniskens P, Cody GD (2014) Diamond xenolith and matrix organic matter in the Sutter’s Mill meteorite measured by C-XANES. Meteoritics&Planetary Science (in Press)
Linke to Article [DOI: 10.1111/maps.12312]

Published in agreement with John Wiley&Sons

¹Yamakawa, A. ¹Yin, Q.-Z.
¹Department of Earth and Planetary Sciences, University of California at Davis, Davis, California, USA

Recent studies have shown that major meteorite groups possess their own characteristic 54Cr values, demonstrating the utility of Cr isotopes for identifying genetic relationships between the planetary materials in conjunction with other classical tools, such as oxygen isotopes. In this study, we performed Cr isotope analyses for whole rocks and chemically separated phases of the new CM2 chondrite, Sutter’s Mill (SM 43 and 51). The two whole rocks of Sutter’s Mill show essentially identical ε54Cr excesses (SM 43 = +0.95 ± 0.09ε, SM 51 = +0.88 ± 0.07ε), relative to the Earth. These values are the same within error with that of the CM2-type Murchison (+0.89 ± 0.08ε), suggesting that parent bodies of Sutter’s Mill and Murchison were formed from the same precursor materials in the solar nebula. Large ε54Cr excess of up to 29.40ε is observed in the silicate phase of Sutter’s Mill, while that of Murchison shows 15.74ε. Importantly, the leachate fractions of both Sutter’s Mill and Murchison form a steep linear anticorrelation between ε54Cr and ε53Cr, cross-cutting the positive correlation previously observed in carbonaceous chondrites. The fact that L4 acid leachate fraction contains higher 54Cr excesses than that of L5 step designed to dissolve refractory minerals suggests that spinel is not a major 54Cr carrier. We also note that L5 contains 53Cr anomalies lower than the solar initial value, suggesting it carries a component of nucleosynthetic anomaly unrelated to the 53Mn decay. We have identified five endmember components of nucleosynthetic origin among the early solar system materials.

Reference
Yamakawa A, Yin Q-Z (2014) Chromium isotopic systematics of the Sutter’s Mill carbonaceous chondrite: Implications for isotopic heterogeneities of the early solar system. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12346]

Published by arrangement with John Wiley&Sons

¹Yesiltas, M., ²Kebukawa, Y., ¹Peale, R. E., ³Mattson, E., ³Hirschmugl, C. J., ^4,5Jenniskens, P.
¹Department of Physics, University of Central Florida, Orlando, Florida, USA
²Faculty of Engineering, Yokohama National University, Hodogaya-ku, Yokohama, Japan
³Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
⁴SETI Institute, Mountain View, California, USA
⁵NASA Ames Research Center, Moffett Field, California, USA

Synchrotron-based Fourier transform infrared spectroscopy and Raman spectroscopy are applied with submicrometer spatial resolution to multiple grains of Sutter’s Mill meteorite, a regolith breccia with CM1 and CM2 lithologies. The Raman and infrared active functional groups reveal the nature and distribution of organic and mineral components and confirm that SM12 reached higher metamorphism temperatures than SM2. The spatial distributions of carbonates and organic matter are negatively correlated. The spatial distributions of aliphatic organic matter and OH relative to the distributions of silicates in SM2 differ from those in SM12, supporting a hypothesis that the parent body of Sutter’s Mill is a combination of multiple bodies with different origins. The high aliphatic CH2/CH3 ratios determined from band intensities for SM2 and SM12 grains are similar to those of IDPs and less altered carbonaceous chondrites, and they are significantly higher than those in other CM chondrites and diffuse ISM objects.

Reference
Yesiltas M, Kebukawa Y, Peale RE, Mattson E, Hirschmugl CJ, Jenniskens P (2014) Infrared imaging spectroscopy with micron resolution of Sutter’s Mill meteorite grains. Meteoritics & Planetary Science (in Press)
Link to Article [doi: 10.1111/maps.12321]

Published by arangement with John Wiley&Sons

¹Takaaki Noguchi et al. (>10 Autors)*
¹Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku,
Fukuoka 819-0395, Japan
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Reference
Noguchi T et al. (2014) Mineralogy of four Itokawa particles collected from the first touchdown site.
Earth, Planets and Space 66:124
Link to Article [doi:10.1186/1880-5981-66-124]

¹Alicia Noel,¹Janice L. Bishop,^2,3Muna Al-Samir,²Christoph Gross,
⁵Jessica Flahaut,^2,4Patrick C. McGuire,⁶Catherine M. Weitz,⁴Frank Seelos,⁴Scott Murchie

¹Carl Sagan Center, The SETI Institute, Mountain View, CA 94043, USA
²Planetary Science and Remote Sensing Group, Institute of Geosciences, Freie Universität Berlin, 12249 Berlin, Germany
³DLR, Institute of Planetary Research, Berlin, Germany
⁴Applied Physics Laboratory, Laurel, MD 20723, USA
⁵Earth and Life Sciences, Vrije Universiteit (VU) Amsterdam, Amsterdam, Netherlands
⁶Planetary Sciences Institute, Tucson, AZ 85721, USA

Juventae Chasma is a deep depression located north of Valles Marineris on Mars, with four bright mounds or light-toned interior layered deposits (ILDs) extending upwards from the Canyon floor. We present here the results of long-term imaging of Juventae Chasma including mounds A, B, C, and D using multiple datasets. Monohydrated sulfates (MHS) were deposited first on the canyon floor, followed by polyhydrated sulfates (PHS). The upper PHS-dominated units are largely eroded away at Juventae Chasma, but this material is still present in significant abundance at mound B. PHS are observed mixed with MHS in some areas of mounds A and C. Terraces are observed at the upper elevations of mound B that contain PHS at the steeper slopes and appear to be covered with dust on the horizontal surfaces. Current analyses of the MHS-rich unit indicate that kieserite (MgSO4⋅H2O) is the primary sulfate component, rather than szomolnokite (FeSO4⋅H2O) as previously thought. Formation of kieserite at Juventae Chasma likely required temperatures in the 150–200 °C range. Geochemical modeling is most consistent with dissolution of mafic materials followed by precipitation of kieserite from solution. The dust exhibits ferric signatures and the sand is largely mafic material. Outcrops of olivine- and pyroxene-bearing rocks are best observed along the base of mound C and in the chaotic terrain surrounding mound D. This study summarizes the current understanding of Juventae Chasma and its ILDs using HRSC, HiRISE and CTX data, an expanded laboratory spectral library, and the latest calibrations available for CRISM.

Reference
Noel A, Bishop JL, Al-Samir M, Gross C, Flahaut J, McGuire PC, Weitz CM, Seelos F, Murchie S (2014) Mineralogy, morphology and stratigraphy of the light-toned interior layered deposits at Juventae Chasma. Icarus (in Press)
Link to Article [DOI: 10.1016/j.icarus.2014.09.033]

Copyright Elsevier

¹V. S. Antipin, ¹M. I. Kuz’min, ²D. M. Pecherskii, ³V. A. Tsel’movich, ⁴. A. Yazev
¹Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
²Schmidt Joint Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
³Borok Geophysical Observatory, Schmidt Joint Institute of Physics of the Earth, Russian Academy of Sciences, Borok, Yaroslavl’ oblast, Russia
⁴Irkutsk State University, Irkutsk, Russia

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Reference
Antipin VS, Kuz’min MI, Pecherskii DM, Tsel’movich VA, Yazev SA (2014) The substance of the Chelyabinsk meteorite: Results of geochemical and thermomagnetic studies. Doklady Akademii Nauk 458, 57–60.
Link to Article [10.1134/S1028334X14090013]

¹Min Tang,^1,2Anouk Ehreiser,¹Yi-Liang Li
¹Department of Earth Sciences, The University of Hong Kong, Pokfulam, Hong Kong
²Department of Physics and Astronomy, Heidelberg University, Postfach 10 57 60, 69047 Heidelberg, Germany

Gypsum is a mineral that commonly precipitates in hydrothermal environments. This study reports the electron microscopic analyses of gypsum morphologies and crystal sizes found in hot springs on the Kamchatka Peninsula, Russia, and compares these analyses with gypsum morphologies of hydrothermal genesis found in Lower Cambrian black shale. In sediments of the Kamchatka hot springs, we observed prismatic, prismatic pseudo-hexagonal, fibrous, tubular, lenticular and twinned gypsum crystals, with crystal sizes ranging from 200 μm. The coexistence of diverse crystal habits of gypsum implies a constant interaction between hot spring geochemistry and the metabolisms of the microbial community. The crystallization of Ca- and Ba-sulfates in the black shale of the Lower Cambrian, which shows similar but less varied morphology, was influenced by post-depositional hydrothermal fluids. The partial replacement of pyrite by sulfates in a situation coexisting with rich biomass deposits and animal fossils indicates limited modification of the sedimentary records by biological materials. If the gypsum precipitated on Mars underwent similar interactions between microbial communities and their geochemical environments, the resulting crystal habits could be preserved even better than those on Earth due to the weak geodynamics prevailing on Mars throughout its evolutionary history.

Reference
Tang M, Ehreiser A, Li, Y-L (2014) Gypsum in modern Kamchatka volcanic hot springs and the Lower Cambrian black shale: Applied to the microbial-mediated precipitation of sulfates on Mars. American Mineralogist 99, 2126-2137,
Link to Article: [doi:10.2138/am-2014-4754]

Copyright: The Mineralogical Society of America

¹Si Sun,¹Lung S. Chan,¹Yi-Liang Li

¹Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong

The biological cycling of phosphorus on Earth could be as early as the origin of life in early Archean. However, because of the low abundance and fine particle size, phosphate related to microbial ecophysiological activities in early sedimentary rocks, especially those deposited before the Great Oxidation Event (GOE, ca. 2.45–2.32 Ma), is still poorly addressed. It is not until recently that certain petrographic and mineralogical features of apatite in the early Precambrian sedimentary rocks were found related to microbial activities. In this study, we report high-resolution electron microscopic investigations on apatite from the Neoarchean to early Paleoproterozoic banded iron formations (BIFs), Mesoproterozoic to Lower Cambrian black shale and phosphorites, and Pliocene sediments. Apatite in BIFs occurs as 4–8 μm radial flowers with “petals” made of apatite rods. Their mineralogical and petrologic features are highly similar to those in the younger sedimentary rocks in which biomass have been confirmed to play an important role in the mineralization of phosphate. We suggest that these sedimentary rocks or sediments have experienced similar phosphogenetic processes mediated by biomass that led to the mineralization of phosphorus. The formation and preservation of phosphate (apatite) with conspicuous recognizable features in association with biological activities from Late Archean to Pliocene implies its universal significance in recording microbial processes through deep geological evolution. With mild dynamic processes, the martian (sub)surface has better preservation conditions than Earth, and the micro-structure of phosphate formed in environments mediated by microorganisms could be recognized by high-resolution observations on the surface of Mars or returned samples, if microbial life ever developed on Mars.

Reference
Sun S, Chan LS, Li Y-L (2014) Flower-like apatite recording microbial processes through deep geological time and its implication to the search for mineral records of life on Mars. American Mineralogist 99, 2116-2125
Link to Article [doi:10.2138/am-2014-4794]

Copyright: The Mineralogical Society of America

¹Janice L. Bishop,²Melissa D. Lane,¹M. Darby Dyar,¹Sara J. King, ¹Adrian J. Brown,⁴Gregg A. Swayze
¹SETI Institute, Carl Sagan Center, Mountain View, California 94043, U.S.A.
²Planetary Science Institute, 1700 E. Fort Lowell Road, Suite 106, Tucson, Arizona 85719, U.S.A.
³Department of Astronomy, Mount Holyoke College, South Hadley, Massachusetts 01075, U.S.A.
⁴U.S. Geological Survey, Denver, Colorado 80225, U.S.A.

This study of the spectral properties of Ca-sulfates was initiated to support remote detection of these minerals on Mars. Gypsum, bassanite, and anhydrite are the currently known forms of Ca-sulfates. They are typically found in sedimentary evaporites on Earth, but can also form via reaction of acidic fluids associated with volcanic activity. Reflectance, emission, transmittance, and Raman spectra are discussed here for various sample forms. Gypsum and bassanite spectra exhibit characteristic and distinct triplet bands near 1.4–1.5 μm, a strong band near 1.93–1.94 μm, and multiple features near 2.1–2.3 μm attributed to H2O. Anhydrite, bassanite, and gypsum all have SO4 combination and overtone features from 4.2–5 μm that are present in reflectance spectra. The mid-IR region spectra exhibit strong SO4 ν3 and ν4 vibrational bands near 1150–1200 and 600–680 cm−1 (~8.5 and 16 μm), respectively. Additional weaker features are observed near 1005–1015 cm−1 (~10 μm) for ν1 and near 470–510 cm−1 (~20 μm) for ν2. The mid-IR H2O bending vibration occurs near 1623–1630 cm−1 (~6.2 μm). The visible/near-infrared region spectra are brighter for the finer-grained samples. In reflectance and emission spectra of the mid-IR region the ν4 bands begin to invert for the finer-grained samples, and the ν1 vibration occurs as a band instead of a peak and has the strongest intensity for the finer-grained samples. The ν2 vibration is a sharp band for anhydrite and a broad peak for gypsum. The band center of the ν1 vibration follows a trend of decreasing frequency (increasing wavelength) with increasing hydration of the sample in the transmittance, Raman, and reflectance spectra. Anhydrite forms at elevated temperatures compared to gypsum, and at lower temperature, salt concentration, and pH than bassanite. The relative humidity controls whether bassanite or gypsum is stable. Thus, distinguishing among gypsum, bassanite, and anhydrite via remote sensing can provide constraints on the geochemical environment.

Reference
Bishop JL, Lane MD, Dyar MD, King SJ, Brown AJ, Swayze GA (2014) Spectral properties of Ca-sulfates: Gypsum, bassanite, and Anhydrite. American Mineralogist 99, 2105-2115
Link to Article [doi: 10.2138/am-2014-4756]

Copyright: The Mineralogical Society of America