Results 31 to 40 of about 441 (171)
Laboratory technology and cosmochemistry [PDF]
Proceedings of the National Academy of Sciences, 2011 Recent developments in analytical instrumentation have led to revolutionary discoveries in cosmochemistry. Instrumental advances have been made along two lines: (i) increase in spatial resolution and sensitivity of detection, allowing for the study of increasingly smaller samples, and (ii) increase in the precision of isotopic analysis that allows more
Zinner, Ernst +2 more
openaire +3 more sources
Thermochemical equilibrium calculations of high-temperature O2 generation on the early Earth: Giant asteroid impact on land [PDF]
Journal of the Serbian Chemical Society, 2003 Earth’s atmosphere is composed primarily of N2 and O2. The origin of free O2 in the early Earth’s atmosphere is still subject of considerable debate.1 Theoretical models suggest that the initial form of free O2 in the atmosphere has been oceanic H2O ...
Premović Pavle I.
doaj +1 more source
Frontiers in Earth Science, 2021 The δ18O values of submarine vent fluids are controlled by seawater-basalt exchange reactions, temperature of exchange, and to a lesser extent, by phase separation.
D. O. Zakharov +3 more
doaj +1 more source
The vanadium isotopic constitution of petroleum asphaltenes: La Luna Formation (Venezuela) [PDF]
Journal of the Serbian Chemical Society, 2000 High resolution mass spectrometry indicates that the isotopic abundance of 50Vanadium (V) of the Late Cretaceous La Luna petroleum asphaltenes and related source kerogen of marine origin (both highly enriched with V > 2000 ppm) is higher by ...
Premović Pavle I. +7 more
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The Astrophysical Journal Letters, 2023 We present a U-corrected Pb–Pb age of 4566.19 ± 0.20 Ma (1.11 ± 0.26 Myr after t _0 ) for the moderately volatile element rich, andesitic meteorite Erg Chech 002 (EC002). Our Al–Mg isochron defines a ^26 Al/ ^27 Al initial ratio of (8.65 ± 0.09) × 10 ^−6
J. N. Connelly +5 more
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Геофизический журнал, 2019 The history of origin and evolution in Ukraine of mineralogical studies of cosmic samples, mainly meteorites, and the main stages of formation of the Department of Сosmoecology and Cosmic Mineralogy at the M. P.
V. P. Semenenko
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Heidelberger Jahrbücher Online, 2017 The NASA Stardust mission returned the first tiny samples of interstellar dust from beyond the borders of our solar system. This region is almost devoid of matter and the interstellar dust particles floating through our solar system are extremely rare ...
Andrew J. Westphal, Mario Trieloff
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CHIMIA, 2022 Due to the development of multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) around 25 years ago, the isotopes of a large range of elements (masses from Li to U) are now analyzed with high enough precision and accuracy to resolve ...
Nicolas Greber, Kirsten van Zuilen
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Geostandards and Geoanalytical Research, Volume 50, Issue 2, Page 341-367, June 2026.Key Points We recommend using the notation δ122/118SnNIST SRM 3161a for mass‐dependent Sn isotope data. We derived conversion factors relative to NIST SRM 3161a for Puri Sn CEZA (0.132 ± 0.011‰), Sn Lyon (0.229 ± 0.016‰), Sn IPGP (0.162 ± 0.018‰). Tin isotope compositions are presented for SPEX CertiPrep Sn and nine USGS reference materials.
Aurélia C.E. Meister +10 more
wiley +1 more source
An unsupervised machine learning approach to iron meteorite classification
Meteoritics &Planetary Science, Volume 61, Issue 6, Page 997-1011, June 2026.Abstract Iron meteorites are usually classified manually using bivariate elemental plots. This study extends iron meteorite classification into multi‐element space. We present a computational method for the classification of iron meteorites by applying unsupervised machine learning using density‐based cluster analysis.
Louis‐Alexandre Lobanov, Hilary Downes
wiley +1 more source