Results 121 to 130 of about 1,985 (228)

Carbonic anhydrase traced by cadmium isotope fractionations in Archean to Holocene stromatolitic carbonates

open access: yesCommunications Earth & Environment
Stromatolites record interactions of the biosphere, atmosphere, and hydrosphere. The evolution of C-fixation via diverse metabolisms is linked to metal availability for enzymes such as carbonic anhydrase.
Simon V. Hohl   +4 more
doaj   +1 more source

The 40K‐K dating system: 1. Improving data interpretation using new model calculations

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The 40K‐K cosmic‐ray exposure (CRE) dating system offers a promising method for determining exposure ages of iron meteorites by combining the radioactive cosmogenic 40K with the stable cosmogenic isotopes 39K and 41K. However, earlier applications relied on semi‐empirical production models and inconsistent analytical data sets, limiting their ...
Farshid Nozarian   +2 more
wiley   +1 more source

Impact provenance and age of a unique basalt found in Apollo 12 regolith

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Basaltic sample 12032,366‐18 from the Apollo 12 landing site is distinct among basalts collected at this site, other Apollo landing sites, and lunar meteorites in terms of its age, bulk rock composition, and isotopic composition. We present new Pb isotopic data obtained by in situ Secondary Ion Mass Spectrometry on multiple mineral phases in ...
C. Deligny   +5 more
wiley   +1 more source

Oxygen isotope variability in the IIIAB iron meteorites and their relationship to main group pallasites

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The light element distribution in planetary cores and the processes driving core evolution in rocky planets are poorly understood. Magmatic iron meteorites are samples from the cores of ancient embryonic planetesimals and therefore provide a window into the processes governing core evolution. We performed high precision oxygen isotope analyses
R. J. Windmill   +4 more
wiley   +1 more source

Characterization of ferric hydroxysulfate on Mars and implications of the geochemical environment supporting its formation

open access: yesNature Communications
Sulfate minerals are significant components of the martian surface and provide clues about the martian geochemical environment. One unusual Fe-sulfate phase has been intriguing Mars scientists for over a decade due to its unique spectral bands that are ...
J. L. Bishop   +17 more
doaj   +1 more source

Microstructural evidence for multiple generations of sulfide precipitation and impact‐induced thermal alteration under acidic conditions on Asteroid Ryugu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Here we report on the microstructure and chemistry of sulfide minerals returned from asteroid (162173) Ryugu. We identify a unique sulfide population in particle A0016 composed of violarite (FeNi2S4), pyrite (FeS2), chalcopyrite (CuFeS2), pyrrhotite (Fe1‐xS), and pentlandite ([Fe,Ni]9S8).
M. C. Benner   +3 more
wiley   +1 more source

Crystallization of dmisteinbergite (hexagonal CaAl2Si2O8) from type B CAI analog melt

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Dmisteinbergite is a metastable polymorph of CaAl2Si2O8, which has been found in calcium−aluminum‐rich inclusions (CAIs) in chondrites, although anorthite is the predominant CaAl2Si2O8 phase in natural type B CAIs. The occurrence/absence of igneous dmisteinbergite would put tighter constraints on the thermal history of CAIs.
Yasuaki Tsuruoka   +6 more
wiley   +1 more source

Nature, origin, and phosphorylation potential of the phosphorus/sulfur‐bearing nanoscale multiphasic assemblages in the CM chondrites Murchison and Murray

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Carbonaceous chondrites contain phosphorus, whose speciation and thus history remain to be investigated. Phosphorus/sulfur‐bearing assemblages have been reported in carbonaceous CM chondrites, but there is no consensus about their exact compositions and origins.
Valentine Megevand   +4 more
wiley   +1 more source

Importance of mineralogical spectroscopy on planetary exploration.

open access: yesJapanese Magazine of Mineralogical and Petrological Sciences, 2002
openaire   +2 more sources

The first discovery of a shocked, metasomatised CV3 chondrule‐fragment in a (Al,Cu)‐bearing micrometeorite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report the discovery of the second (Al,Cu)‐alloy–bearing micrometeorite, FB‐A2, recovered from Mount Gariglione (southern Italy), representing the sixth such occurrence worldwide. Although chondritic in nature, FB‐A2 differs markedly from previously described microspherules.
Giovanna Agrosì   +6 more
wiley   +1 more source

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