Results 71 to 80 of about 11,238 (241)

Titanium stable isotopic variations in chondrites, achondrites and lunar rocks [PDF]

open access: yes, 2017
Titanium isotopes are potential tracers of processes of evaporation/condensation in the solar nebula and magmatic differentiation in planetary bodies. To gain new insights into the processes that control Ti isotopic variations in planetary materials, 25 ...
Puchtel, Igor S.   +10 more
core   +3 more sources

Chondrule size averaging in two and three dimensions

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Chondrule sizes are an important discriminant of chondrite groups and chondrule formation theories. Yet most studies report 2‐D sizes without attempting the somewhat tedious corrections to 3‐D proposed in the past literature. I show here that 3‐D size averages can be simply calculated directly from 2‐D averages of appropriate powers of sizes ...
Emmanuel Jacquet
wiley   +1 more source

Two faces of L-type asteroids

open access: yesAstronomy & Astrophysics
Context. L-types are a rare class of asteroids whose spectra indicate similarities with CO and CV chondrites, suggesting high abundances of refractory inclusions, particularly with respect to the calcium-aluminium-rich inclusion.
Mahlke M.   +8 more
doaj   +1 more source

TAXONOMIC REVIEW OF CHONDRITES AFFINIS (STERNBERG, 1833) FROM CRETACEOUS-NEOGENE OFFSHORE-DEEP-SEA TETHYAN SEDIMENTS AND RECOMMENDATION FOR ITS FURTHER USE

open access: yesRivista Italiana di Paleontologia e Stratigrafia, 2012
The branched trace fossil Chondrites affinis (Sternberg, 1833), synonymised so far with C. targionii (Brongniart, 1828), has been analyzed in an exceptionally well preserved specimen from the Saraceno Formation (?Upper Cretaceous; ?Eocene-Miocene) in the
ALFRED UCHMAN   +2 more
doaj   +1 more source

Thermal history of an amoeboid olivine aggregate in the early solar nebula

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Carbonaceous chondrites commonly contain amoeboid olivine aggregates (AOAs). Here, we investigated an AOA in the CR chondrite Y‐793261. This AOA contains an unstable assemblage of forsterite and quartz. We found a rare occurrence of enstatite and quantitatively discuss its formation process.
M. Kimura   +3 more
wiley   +1 more source

The effect of terrestrial weathering on the magnetic properties of meteorites from the Atacama Desert

open access: yesУчёные записки Казанского университета: Серия Естественные науки
Once ordinary chondrites fall on Earth, Fe–Ni minerals and troilite they contain oxidize and transform into iron oxyhydroxides and/or iron oxides, which is expected to modify their magnetic properties.
D. Kuzina   +6 more
doaj   +1 more source

Distribution and rare earth element abundances of apatite in Bennu samples determined by synchrotron X‐ray fluorescence spectroscopy

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Apatite is often the most rare earth element (REE)‐enriched mineral in chondritic meteorites. REE enrichment and fractionation levels in apatite grains can give insight into the aqueous fluids in which they formed and the conditions prevailing within the host body. In this study, we applied synchrotron X‐ray fluorescence (SXRF) spectroscopy to
B. J. Tkalcec   +17 more
wiley   +1 more source

A Classification of Several Yamato-74 Chondrites [PDF]

open access: yes, 1979
P(論文)Six Yamato-74 chondritic meteorites have been classified, based on iron contents of olivines and orthopyroxenes in their small fragments. The results are as follows : Yamato-74193,-74498 and -74507 are H4-chondrites, Yamato-74367 and -74603 are L4 ...
Ohtsuka, Yoshiro   +2 more
core  

The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites [PDF]

open access: yes
The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the ...
Amelin, Yuri   +10 more
core   +2 more sources

VUV and mid‐UV photoabsorption cross sections of thin films of glycine and alanine: Application to their photochemistry in the solar system

open access: yesPhotochemistry and Photobiology, EarlyView.
Thin solid films of pure glycine or alanine (thicknesses ranging from 10 to 700 nm) were prepared on MgF2 windows using a vacuum sublimation/recondensation method. VUV‐UV spectroscopy of these films enabled us to characterize new absorption cross sections for glycine and alanine for VUV‐UV radiations between 120 and 300 nm.
Juliette Pastore   +6 more
wiley   +1 more source

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