Results 71 to 80 of about 37,639 (216)

New Magnetite Reference Material for SIMS δ18O Measurements and a Study of Precision and Accuracy Due to Crystal Orientation Effects

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points A new magnetite reference material (PF21mt) is available for δ18O measurements by SIMS. Reproducibility of measurement results in two laboratories suggest orientation bias of ±2‰ (2s) at 20 keV. Repeatability improves to ±1‰ (2s) when using a 13 keV protocol, suggesting reduced orientation bias. In situ isotope ratio measurements provide the
Michelle Ulrich   +4 more
wiley   +1 more source

A Tale of Three Galaxies: Deciphering the Infrared Emission of the Spectroscopically Anomalous Galaxies IRAS F10398+1455, IRAS F21013-0739 and SDSS J0808+3948

open access: yes, 2015
The \textit{Spitzer}/Infrared Spectrograph spectra of three spectroscopically anomalous galaxies (IRAS~F10398+1455, IRAS~F21013-0739 and SDSS~J0808+3948) are modeled in terms of a mixture of warm and cold silicate dust, and warm and cold carbon dust ...
Hao, Lei   +3 more
core   +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

The structure and petrology of the Cnoc nan Cuilean Intrusion, Loch Loyal Syenite Complex, NW Scotland [PDF]

open access: yes, 2013
In NW Scotland, several alkaline intrusive complexes of Silurian age intrude the Caledonian orogenic front. The most northerly is the Loch Loyal Syenite Complex, which is divided into three separate intrusions (Ben Loyal, Beinn Stumanadh and Cnoc nan ...
Goodenough, Kathryn M.   +5 more
core   +3 more sources

Small‐scale elemental abundance variations in Ryugu particles from touchdown 1

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Ryugu materials closely resemble CI chondrites' mineralogical, chemical, and isotopic compositions; yet minor but resolvable differences in certain elemental abundances are evident. In this study, the bulk chemical compositions of eight individual Ryugu particles (1.5–4.3 mg) from the first touchdown site (TD1) were determined using triple ...
Karina López García   +6 more
wiley   +1 more source

Mineral Chemistry Studies on Pyroxenes in Fe Skarns in the West of Elazığ (Turkey); Their Role in the Skarn Mineralization Process

open access: yesApplied Sciences
This study presents the first detailed investigation of pyroxene zoning within polymetallic skarn zones of the Elazığ region. Skarns develop along contacts between plutonic rocks (diorite and granite) and carbonate rocks, forming two main zones ...
Necla Koprubasi   +2 more
doaj   +1 more source

Petrography and mineral chemistry of Northeast Africa 053—A remnant of Martian crystal mush

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract In Earth's igneous systems, crystal mushes, crystal‐rich frameworks permeated by silicate melt, represent a common and fundamental stage in the evolution of magma bodies. However, whether crystal mushes occur within Martian igneous systems and play a comparable role is unknown. Here, we present a comprehensive petrography and mineral chemistry
Xhonatan Shehaj   +2 more
wiley   +1 more source

Biotite composition constrains Tongling skarn Cu–Au mineralization, eastern China

open access: yesSolid Earth Sciences
Skarn Cu, Au deposits are most important deposit-type in the Tongling region, eastern China, where skarn Au deposits are closely associated with pyroxene monzodiorite, and skarn Cu deposits are genetically related to quartz monzodiorite and granodiorite.
Sujuan Zhou   +7 more
doaj   +1 more source

Diffusion kinetics of 3He in pyroxene and plagioclase and applications to cosmogenic exposure dating and paleothermometry in mafic rocks [PDF]

open access: yesGeochronology
In this study, we investigate the diffusivity of cosmogenic 3He in a variety of plagioclase and pyroxene compositions, and its application to paleothermometry and exposure dating in these minerals, through stepwise degassing experiments. While cosmogenic
M. Bergelin   +5 more
doaj   +1 more source

Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang [PDF]

open access: yes, 2011
Hibonite-bearing Ca,Al-rich inclusions (CAIs) usually occur in CM and CH chondrites and possess petrographic and isotopic characteristics distinctive from other typical CAIs.
Guan, Yunbin, Hsu, Weibiao, Wang, Ying
core  

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