Mineralogy and geochemistry of hot spring deposits at Námafjall, Iceland: Analog for sulfate soils at Gusev crater, Mars

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).

The crystal structure and chemistry of natural giniite and implications for Mars

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

Mineralogy and bulk geochemistry of a fumarole at Hverir, Iceland: Analog for acid-sulfate leaching on Mars

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.

The catalog of the meteorite collection of the Italian Museum of Planetary Sciences in Prato (Italy)

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.

Impacts on the CV parent body: A coordinated, multiscale fabric analysis of the Allende meteorite

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.

Degassing of early-formed planetesimals restricted water delivery to Earth

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

In situ oxygen, magnesium, and silicon isotopic compositions of the FUN inclusion Vigarano 1623-5

1,2Johanna Marin-Carbonne,1Kevin D. McKeegan,3,4Andrew M. Davis,5Glenn J. MacPherson,5Ruslan A. Mendybaev,5Frank M. Richter
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.13971]
1Department of Earth, Planetary, and Space Sciences, University of California—Los Angeles, Los Angeles, California, USA
2Institut des Sciences de la Terre, Université de Lausanne, Lausanne, Switzerland
3Department of the Geophysical Sciences, University of Chicago, Illinois, USA
4Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
5Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
Published by arrangement with John Wiley & Sons

Oxygen, magnesium, and silicon isotopic abundances in Vigarano 1623-5 were studied using secondary ion mass spectrometry to investigate correlations between isotopic and petrologic properties of this unique forsterite-bearing FUN inclusion. Vigarano 1623-5 displays large, correlated mass-dependent fractionation effects, tightly linked to mineralogy within distinct petrologic units of the inclusion. The pyroxene-rich and melilite-rich interior parts of the inclusion display highly mass-fractionated isotopic compositions of oxygen, magnesium, and silicon, consistent with Rayleigh distillation during evaporation of a melt with initial oxygen composition close to a solar composition. However, the chemical composition, enriched in magnesium and silicon, suggests a precursor already fractionated by prior melt evaporation. A discontinuous igneous rim was produced by a flash-melting event followed by isotopic exchange in the rim melilite with planetary-like oxygen, mechanical fragmentation, and reassembly with an accretionary rim of heterogeneous materials. Al-rich minerals in 1623-5 show evidence for having crystallized with live 26Al but at less than the “canonical” level of most CV calcium-aluminum-rich inclusions. However, well-defined 26Al-26Mg isochrons are not found and temporal implications are ambiguous.

Shock-induced potassium and zinc isotope fractionation in ordinary chondrites and its implications

1,2,3Ying-Kui Xu,1,4Zhi Li,1,2Shi-Jie Li,3Ze-Zhou Wang,1,4De-Liang Wang,1,5Yan Fan,1,2Xiong-Yao Li,1,2Jian-Zhong Liu,6,2Dan Zhu
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2023.03.031]
1Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
2CAS Center for Excellence in Comparative Planetology, Hefei, 230022, China
3Isotope Laboratory, Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
4University of Chinese Academy of Sciences, Beijing, 100049, China
5Department of Geology, Northwest University, Xi’an, 710069, China
6State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
Copyright Elsevier

To constrain how impacts influence the behavior of moderately volatile elements (MVEs), we report potassium (K) and zinc (Zn) contents and isotopic compositions of shock melt pockets (SMPs) and unmelted parts of three heavily shocked ordinary chondrites and bulk rocks of Chelyabinsk meteorite. All SMPs are enriched in K content and have lower isotopic values (δ41K = -1.99‰, -1.22‰ and -1.40‰) while the adjacent unmelted parts are enriched in heavy K isotopes (δ41K = -0.41‰, -0.01‰ and 0.04‰) compared to the bulk rocks of Chelyabinsk meteorite (δ41K = -0.77‰ and -0.73‰). By contrast, Zn is depleted in SMPs and the isotopic compositions are heavier (δ66Zn = -0.19‰, 2.42‰, 1.74‰) in SMPs than that in unmelted parts (δ66Zn = -0.65‰, 1.76‰, -0.97‰). Our results indicate a decoupling between the two MVEs that Zn is lost from shock melts while K is dramatically enriched in shock melts during impacts. The isotope fractionation of Zn is probably caused by evaporation of shock melts, while K isotope fractionation is most likely caused by solid-melt diffusion which is controlled by its incompatibility. The isotopic decoupling of K from Zn during major impacts further enhances our understanding of high temperature elemental and isotopic behavior of MVEs and may shed new light on the variously heterogeneous distribution of MVEs in solar system.

Trends in planetary science research in the Puna and Atacama Desert regions: Underrepresentation of local scientific institutions?

1A. Tavernier,2,3G. A. Pinto,4,5,6M. Valenzuela,1A. Garcia,1C. Ulloa,7R. Oses,8,9,10,11B. H. Foing
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13972]
1Instituto de Investigaciones Científicas y Tecnológicas, IDICTEC, Laboratorio de Investigacion de la Criosfera y Aguas, Universidad de Atacama, UDA, Copiapó, Chile
2Instituto de Investigación en Astronomía y Ciencias Planetarias, INCT, Universidad de Atacama, UDA, Copiapó, Chile
3Centre de Recherches Pétrographiques et Géochimiques, CRPG, Université de Lorraine, Nancy, France
4Departamento de Ciencias Geológicas, Universidad Católica del Norte, UCN, Antofagasta, Chile
5Millennium Institute of Astrophysics, MAS, Santiago, Chile
6Center for Excellence in Astrophysics and Associated Technologies, CATA, Santiago, Chile
7Centro Regional de Investigacion y Desarrollo Sustentable de Atacama, CRIDESAT, Universidad de Atacama, UDA, Copiapó, Chile
8Instituto de Investigación en Astronomía y Ciencias Planetarias, INCT, Universidad de Atacama, UDA, Copiapó, Chile
9International Lunar Exploration Working Group, ILEWG, EuroMoonMars, Noordwijk, The Netherlands
10Vrije Universiteit Amsterdam, VUA, Amsterdam, The Netherlands
11Universiteit Leiden, Leiden, The Netherlands
Published by arrangement with John Wiley & Sons

In 2019, while launching a multidisciplinary research project aimed at developing the Puna de Atacama region as a natural laboratory, investigators at the University of Atacama (Chile) conducted a bibliographic search identifying previously studied geographic points of the region and of potential interest for planetary science and astrobiology research. This preliminary work highlighted a significant absence of local institutional involvement in international publications. In light of this, a follow-up study was conducted to confirm or refute these first impressions, by comparing the search in two bibliographic databases: Web of Science and Scopus. The results show that almost 60% of the publications based directly on data from the Puna, the Altiplano, or the Atacama Desert with objectives related to planetary science or astrobiology do not include any local institutional partner (Argentina, Bolivia, Chile, and Peru). Indeed, and beyond the ethical questioning of international collaborations, Latin-American planetary science deserves a strategic structuring, networking, as well as a road map at national and continental scales, not only to enhance research, development, and innovation, but also to protect an exceptional natural heritage sampling extreme environmental niches on Earth. Examples of successful international collaborations such as the field of meteorites, terrestrial analogs, and space exploration in Chile or astrobiology in Mexico are given as illustrations and possible directions to follow to develop planetary science in South America. To promote appropriate scientific practices involving local researchers, possible responses at academic and institutional levels will eventually be discussed.