Results 21 to 30 of about 517 (188)

A Common Reference Material for Mass‐Dependent Sn Isotope Compositions: An Inter‐Laboratory Calibration Approach

open access: yesGeostandards and Geoanalytical Research, EarlyView.
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

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis   +5 more
wiley   +1 more source

Shock metamorphism of ordinary chondrites

open access: yesGeochimica et Cosmochimica Acta, 1991
AbstractA revised petrographic classification of progressive stages of shock metamorphism of ordinary chondrites is proposed. Six stages of shock (S1 to S6) are defined, based on shock effects in olivine and plagioclase as recognized by thin section microscopy.
Stöffler, Dieter   +2 more
openaire   +1 more source

Re-assessing the ordinary chondrites paradox [PDF]

open access: yesAstronomy and Astrophysics, 2010
Context. The so-called ordinary chondrite paradox has been a recurring topic in planetary science in the past twenty years. This paradox originated from the first comparisons between spectrophotometric measurements of meteorites and asteroids. Basically it is based on the lack of spectral analogs of the ordinay chondrites (OC) among the Main Belt ...
T. Mothé-Diniz   +5 more
openaire   +1 more source

Noble gases and nitrogen in material from asteroid Bennu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty   +7 more
wiley   +1 more source

Microspherules Formed by Lightning Strikes

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley   +1 more source

Intermediate-sulfidation Style of Epithermal Base Metal (Ag) Mineralization at the Qoyjeh Yeylaq Deposit, SW Zanjan – IRAN

open access: yesJournal of Economic Geology, 2020
Introduction The Qoyjeh Yeylaq Pb-Zn (Ag) deposit located 120 km southeast of Zanjan, is situated in the Urumieh-Dokhtar magmatic arc. apart from Prior to this research no work has been published on Pb-Zn (Ag) mineralization at the Qoyjeh Yeylaq ...
Hossein Bagherpour   +4 more
doaj   +3 more sources

GROUPS OF METEORITE-PRODUCING METEOROIDS AND METEORITES IN ASTEROIDAL ORBITS AND THEIR SOURCES

open access: yesOdessa Astronomical Publications, 2020
This paper presents the results of the analysis of possible existence of nine near-Earth meteorite-producing groups in asteroidal orbits, consisting of sporadic fireballs from the IAU MDC 2007 database, sporadic meteors from the SonotaCo database ...
Yu. M. Gorbanev   +2 more
doaj   +1 more source

Formation mechanisms of ringwoodite: clues from the Martian meteorite Northwest Africa 8705

open access: yesEarth, Planets and Space, 2021
Ringwoodite and wadsleyite are the high-pressure polymorphs of olivine, which are common in shocked meteorites. They are the major constituent minerals in the terrestrial mantle.
Ting Zhang   +7 more
doaj   +1 more source

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska   +6 more
wiley   +1 more source

Home - About - Disclaimer - Privacy