¹Yves Marrocchi,¹Thomas Rigaudier,¹Maxime Piralla,¹Laurette Piani
Earth and Planetary Science Letters 611, 118151 Link to Article [https://doi.org/10.1016/j.epsl.2023.118151]
¹Université de Lorraine, CNRS, CRPG, UMR 7358, Nancy, France
Copyright Elsevier

The conditions and environments in which hydrated phases in unequilibrated meteorites formed remain debated. Among carbonaceous chondrites, Mighei-type chondrites (CMs) display a large range in the degree of aqueous alteration, and thus record different stages of hydration and alteration. Here, we report the bulk H, C, and N contents, H and C isotopic compositions, and thermogravimetric signatures of the most- and least-altered CMs known so far, Kolang and Asuka 12236, respectively. We also report in-situ SIMS measurements of the hydrogen isotopic compositions of water in both chondrites. Compared to other CMs, Asuka 12236 has the lowest bulk water content (3.3 wt.% H2O) and the most D-rich water and bulk isotopic compositions (δD = 180‰ and 280‰, respectively). Combined with literature data, our results show that phyllosilicate-bearing CMs altered to varying degrees accreted water-ice grains with similar isotopic compositions. These results demonstrate that the hydrogen isotopic variations in CM chondrites (i) are not controlled by secondary alteration processes and (ii) were mostly shaped by interactions between the protoplanetary disk and the molecular cloud that episodically fed the disk over several million years. The minimally altered CM chondrites Paris and Asuka 12236 display peculiar, D-rich, hydrogen isotopic compositions that imply the presence of another H-bearing component in addition to insoluble organic matter and phyllosilicates. This component is most likely the hydrated amorphous silicates that are ubiquitous in these chondrites. CM bulk H and O isotopic compositions are linearly correlated, implying that (i) amorphous silicates in CM matrices were already hydrated by disk processes before the onset of CM parent-body alteration, and (ii) the quest for a hypothetically water-free CM3 is illusory.

¹Shui-Jiong Wang,²Shi-Jie Li,³Yangting Lin,¹Si-Zhang Sheng
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2023.04.004]
¹State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
²Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
³Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China]
Copyright Elsevier

We present high-precision mass-dependent nickel isotopic data for a comprehensive suite of achondrites and lunar rocks, providing key insights into the early planetary differentiation and Earth-Moon system formation. The primitive achondrites display high Ni contents and invariant Ni isotopic compositions. Incomplete core-mantle differentiation in primitive achondrite parent bodies resulted in the retention of metal in the mantle, which dominated the Ni budget and accounted for the bulk chondritic Ni isotopic values. The highly reduced differentiated achondrites, aubrites and an ungrouped achondrite (NWA 8409), have variable, and extremely light Ni isotopic compositions. Acid leaching experiments demonstrate that the sulfides are a significant host of light Ni isotopes in aubrites. The most extreme Ni isotope values of aubrites may be due to large Ni isotope fractionation accompanied by silicate-sulfide-metal separation during differentiation of the parent bodies, and subsequent global disruptive collision and reassembly with variably high proportions of sulfides enriched in the mantle. The howardite-eucrite-diogenite (HED) meteorites show Ni isotopic variations that are positively correlated with Ni/Co ratios, a feature that cannot be produced by igneous differentiation. Late accretion of high-Ni and high-Ni/Co chondritic materials after core formation of their likely parent body, Vesta, could have accounted for this correlation. Thus, the primitive silicate mantle of Vesta may have sub-chondritic Ni isotopic compositions, implying possible Ni isotope fractionation during core-mantle differentiation of small planet bodies. The lunar breccia meteorites have homogenously chondritic Ni isotope values, together with their high Ni/Co of bulk rock and metals therein, suggesting impact contamination. Lunar basalt meteorites have low Ni/Co ratios and are systematically isotopically lighter than the breccias, displaying a positive correlation between Ni isotope value and Ni/Co ratio, as that seen in the HEDs. Therefore, the Ni isotopic systematics in lunar rocks also indicates the effect of late accretion, with the primitive lunar mantle having sub-chondritic Ni isotope values. This implies that the Moon-forming impactor, Theia, was likely an aubrite-like differentiated planetary body whose mantle was enriched in light Ni isotopes. We suggest that there was significant Ni isotope fractionation between core and mantle during differentiation of early formed small planetary bodies, but this signature can be obscured by late accretion in the bulk achondrite records.

^1,2Toshimori Sekine,²Tsubasa Tobase,³Youjun Zhang,⁴Ginga Kitahara,⁴Akira Yoshiasa,⁵Tomoko Sato,⁶Takamichi Kobayashi,⁷Akihisa Mori
American Mineralogist 108, 686-694 Link to Article [http://www.minsocam.org/msa/ammin/toc/2023/Abstracts/AM108P0686.pdf]
¹Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
²Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
³Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
⁴Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
⁵Department of Earth and Planetary Systems Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
⁶National Institute for Materials Science, Tsukuba 305-0044, Japan
⁷Department of Mechanical Engineering, Sojo University, Kumamoto 860-0082, Japan
Copyright: The Mineralogical Society of America

Heavy meteorite impacts on Earth’s surface produce melt and vapor that are quenched rapidly and
scattered over wide areas as natural glasses with various shapes and characteristic chemistry, which
are known as tektites and impact glasses. Their detailed formation conditions have long been debated
using mineralogical and geochemical data and numerical simulations of impact melt formations. These
impact processes are also related to the formation and evolution of planets. To unravel the formation
conditions of impact-induced glasses, we performed shock recovery experiments on a tektite. Recovered samples were characterized by X-ray diffraction, Raman spectroscopy, and X-ray absorption fine
structure spectroscopy on the Ti K-edge. Results indicate that the densification by shock compression
is subjected to post-shock annealing that alters the density and silicate-framework structures but that
the local structures around octahedrally coordinated Ti ions remain in the quenched glass. The relationship between the average Ti-O distance and Ti K pre-edge centroid energy is found to distinguish the
valance state of Ti ions between Ti4+ and Ti3+ in the glass. This relationship is useful in understanding
the formation conditions of impact-derived natural glasses. The presence of Ti3+ in tektites constrains
the formation conditions at extremely high temperatures or reduced environments. However, impact
glasses collected near the impact sites do not display such conditions, but instead relatively mild and
oxidizing formation conditions. These different formation conditions are consistent with the previous
numerical results on the crater size dependence.

¹George L. Carson,¹Lindsay J. McHenry,²Brian M. Hynek,¹Barry I. Cameron, ¹Chase T. Glenister
American Mineralogist 108, 637-652 Link to Article [http://www.minsocam.org/msa/ammin/toc/2023/Abstracts/AM108P0637.pdf]
¹Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, Wisconsin 53211, U.S.A.
²Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, 1234 Innovation Drive, Boulder, Colorado 80303, U.S.A.
Copyright: The Mineralogical Society of America

Iceland’s Námafjall geothermal area exhibits a range of alteration environments. Geochemical and
mineralogical analyses of fumaroles and hot springs interacting with Holocene basaltic lavas at Hverir,
and with Pleistocene hyaloclastites atop nearby Námaskarð hill, reveal different patterns of alteration
depending on water-rock ratio, degree of oxidation, and substrate composition and age. The focus of
this study is on the mineral deposits at and near hot springs at Hverir and Námaskarð. Surface samples,
and samples collected from shallow pits in the alteration aprons adjacent to hot springs, were analyzed
by X-ray diffraction (XRD) and X-ray fluorescence (XRF) to constrain the differences in composition
with both distance and depth. Fluids were analyzed in the field for their environmental parameters and
sampled for cation and anion analysis. Fluid analyses revealed uniformly acidic conditions but with
site-to-site variation in other parameters such as temperature, salinity, and conductivity. Solid phases
identified include amorphous silica, pyrite, elemental sulfur, and kaolinite in the muds, surrounded by
Fe2+-sulfate and then Fe3+-sulfate efflorescence, following a redox gradient pattern involving the oxidation of sulfur and then iron with increasing distance. Shallow pits excavated near two Námaskarð hot
springs reveal a shallow oxidation front, with sulfide-rich materials below a thin surface of sulfates and
elemental sulfur. Silica phases include amorphous silica and quartz. Quartz likely reflects diagenetic
maturation of earlier-formed amorphous silica, under surface hydrothermal conditions.
The high iron content of the substrate basalt and the prevalence of Fe-sulfates and Fe-oxides among
the alteration products make this geothermal area an especially useful analog for potential martian
hydrothermal environments. In particular, these sulfate-rich deposits adjacent to volcanic, acidic hot
springs could provide a helpful comparison for sulfur-rich soils in the Columbia Hills on Mars, where
some of the same minerals have been identified (e.g., ferricopiapite) or inferred (e.g., rhomboclase).

¹Christopher T. Adcock,¹Elisabeth M. Hausrath,²Elizabeth B. Rampe,³Hexiong Yang,³Robert T. Downs
American Mineralogist 108, 430-438Link to Article [http://www.minsocam.org/msa/ammin/toc/2023/Abstracts/AM108P0430.pdf]
¹Department of Geoscience, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154-4010, U.S.A.
²NASA Johnson Space Center, 2101 E NASA Parkway, Houston, Texas 77058, U.S.A. 3
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona 85721-0077, U.S.A.
Copyright: The Mineralogical Society of America

Investigations of planetary processes using phosphate minerals often focus on igneous, recrystallized, or potentially metasomatized minerals, likely as a result of the minerals commonly available for
study within meteorites and lunar samples. However, Mars is a relatively phosphorus-rich planet and
possesses abundant evidence of past aqueous surface interactions. Therefore, secondary phosphate
phases may be important on the martian surface. Giniite [Fe2+Fe4
3+(PO4)4(OH)2·2H2O] is a secondary
phosphate mineral that has been suggested as a potentially significant phase at locations in Gusev Crater
and Meridiani Planum on Mars. Although relatively rare as a natural mineral on Earth, giniite has gained
attention as an important mineral in industry and technology, especially the lithium battery industry,
and the ferrian version of the mineral is often synthesized. This suggests giniite may be important as
an in situ resource utilization (ISRU) target for future extended human missions to Mars. Despite this,
there are few data available on the natural mineral and the last characterization of the structure was
over 40 years ago. There has also been confusion in the literature as to whether giniite is orthorhombic
or monoclinic. In this work we revisit and document the chemistry and crystal structure of natural
giniite from the type locality at the Sandamab pegmatite in Namibia using updated techniques. Our
results refine and update what was previously known regarding the structure and chemistry of giniite
and support the potential of the mineral as a possible martian scientific and resource target for further
study to aid future missions

¹George L. Carson,¹Lindsay J. McHenry,²Brian M. Hynek,¹Barry I. Cameron, ¹Chase T. Glenister
American Mineralogist 108, 409-429 Link to Article [http://www.minsocam.org/msa/ammin/toc/2023/Abstracts/AM108P0409.pdf]
¹Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, Wisconsin 53211, U.S.A.
²Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, 1234 Innovation Drive, Boulder, Colorado 80303, U.S.A
Copyright: The Mineralogical Society of America

Iceland’s Námafjall geothermal area exhibits a range of alteration environments. Geochemical and
mineralogical analyses of fumaroles and hot springs interacting with Holocene basaltic lavas at Hverir,
and with Pleistocene hyaloclastites atop nearby Námaskar∂, reveal different patterns of alteration
depending on the water/rock ratio, degree of oxidation, and substrate composition and age. The focus
of this study is a transect of a Hverir fumarole that has formed a bullseye pattern of alteration of a
Holocene basaltic lava flow. Surface samples and samples collected from shallow pits were analyzed
by X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM) to
constrain changes in mineral assemblage and major elemental composition with both distance and
depth. Elemental sulfur is concentrated near the vent, with leached deposits with amorphous silica
and anatase nearby and kaolinite, hematite, and jarosite/alunite-group sulfate minerals farther out,
with smectites and less altered material at the margins, though smaller-scale mineralogical diversity
complicates this pattern.
Silica phases include amorphous silica (most samples), cristobalite (some samples in the leached
part of the apron), and quartz (minor constituent of a few samples). The silica was concentrated through
residual enrichment caused by leaching and is accompanied by a significant enrichment in TiO2 (in
anatase). The presence of abundant cristobalite in a surface fumarole-altered Holocene basaltic lava
flow most likely reflects cristobalite formed during the devitrification of volcanic glass or precipitation
from fumarolic vapors, rather than high-temperature processes. Minor, localized quartz likely reflects
diagenetic maturation of earlier-formed amorphous silica, under surface hydrothermal conditions.
Natroalunite, natrojarosite, and jarosite are all present and even exhibit compositional zonation within
individual crystals, showing that under surface hydrothermal conditions, these minerals can form a
significant solid solution.
The high iron content of the substrate basalt and the prevalence of Fe-sulfates and Fe-oxide spherules
among the alteration products makes this geothermal area an especially useful analog for potential
martian hydrothermal environments. The residual enrichment of silica in the leached deposits of the
Hverir fumarole apron could serve as an acid-sulfate leaching model in which amorphous silica forms
without appreciable sulfur-bearing phases in many samples, a possible analog for silica-rich soils in
the Columbia Hills on Mars. The coexistence of hematite spherules and jarosite-group minerals serves
as an intriguing analog for a volcanic/hydrothermal model for hematite and jarosite occurrences at
Meridiani Planum.

¹Tutolo,²Benjamin M.
Science Advances Open Access Link to Article [DOI10.1126/sciadv.add8472]
¹University of Calgary, Department of Geoscience, Calgary, AB, Canada
²University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom

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

¹Marco Morelli,^2,3Annarita Franza,¹Daniela Faggi,¹Giovanni Pratesi
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.13974]
¹Parsec Foundation, Via di Galceti 74, 59100 Prato, Italy
²Department of Earth Sciences, University of Firenze, Via G. La Pira, 4, 50121 Firenze, Italy
³INAF-IAPS, Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, 00133 Roma, Italy
Published by arrangement with John Wiley & Sons

For the first time, this paper presents to the planetary scientists’ community the catalog of the meteorite collection preserved at the Italian Museum of Planetary Sciences (Museo Italiano di Scienze Planetarie, henceforth MISP) in Prato (Italy). Founded in 2005, MISP is a type specimen official repository approved by the Nomenclature Committee of the Meteoritical Society. It represents one of the few museums worldwide entirely devoted to planetary sciences. The catalog of its meteorite collection encompasses 430 meteorites for a total of 1536 specimens, including 291 thin sections, 184 thick sections, and 278 specimens that MISP has classified. Furthermore, MISP is currently classifying 57 other meteorites. Some samples were found during meteorite recovery expeditions in hot deserts, promoted by MISP in collaboration with diverse Italian universities and national research institutions. MISP also keeps an impact rocks collection comprising 257 samples. In a country like Italy, where most of the collected meteorites are housed in museums whose catalogs are not available online, the publication of the MISP meteorite collection catalog, together with the catalog of the impact rocks collection, represents not only a significant scientific primary source but also a remarkable tool for disseminating meteoritics to nonresearch audiences in educational activities and citizen science projects.

^1,2L. V. Forman,^2,3,4L. Daly,¹P. A. Bland,^1,2,5G. K. Benedix,⁶C. Corrigan
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.13970]
¹Space Science & Technology Centre, School of Earth & Planetary Sciences, Curtin University, Bentley, Western Australia, Australia
²Department of Earth & Planetary Sciences, Western Australian Museum, Perth, Western Australia, Australia
³School of Geographical & Earth Sciences, University of Glasgow, Glasgow, UK
⁴Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales, Australia
⁵Planetary Science Institute, Tucson, Arizona, USA
⁶Department of Mineral Science, National Museum of Natural History (NMNH), Washington, DC, USA
Published by arrangement with John Wiley & Sons

Evidence of impact-induced compaction in the carbonaceous chondrites, specifically CMs and CVs, has been widely investigated utilizing microscopy techniques and impact experiments. Here, we use high-resolution photography and large area and high-resolution electron backscattered diffraction (EBSD) mapping analyses in tandem, to explore the effects of impact-induced compaction at both the meso- and micro-scales in the Allende CV3.6 carbonaceous chondrite. Macro-scale photography images of a ~25 cm slab of Allende captured meso-scale features including calcium-aluminum inclusions (CAIs) and chondrules. CAIs have a long-axis shape-preferred orientation (SPO). Examination of such meso-scale features in thin section revealed the same trend. Matrix grains from this section display a large amount of heterogeneity in petrofabric orientation; microscale, high-resolution, large area EBSD mapping of ~300,000 olivine matrix grains; high-resolution large area EBSD map across an elongate CAI; and a series of high-resolution EBSD maps around two chondrules and around the CAI revealed crystallographic preferred orientations (CPOs) in different directions. Finally, internal grains of the CAI were found to demonstrate a weak lineation CPO, the first crystallographic detection of possible CAI “flow.” All results are consistent with multiple, gentle impacts on the Allende parent body causing hemispheric compaction. The larger, more resistant components are likely to have been compressed and oriented by earlier impacts, and the matrix region petrofabrics and CAI “flow” likely occurred during subsequent impacts. Meteoritic components respond differently to impact events, and consequently, it is likely that different components would retain evidence of different impact events and angles.

¹M. E. Newcombe,²S. G. Nielsen,¹L. D. Peterson,³J. Wang,³C. M. O’D. Alexander,⁴A. R. Sarafian,⁵K. Shimizu,^6,3L. R. Nittler,⁷A. J. Irving
Nature 615, 854-857 Link to Article [DOI https://doi.org/10.1038/s41586-023-05721-5]
¹University of Maryland, College Park, MD, USA
²NIRVANA Laboratories, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
³Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA
⁴Corning Incorporated, Corning, NY, USA
⁵University of Wisconsin, Madison, WI, USA
⁶School Of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
⁷University of Washington, Seattle, WA, USA

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