Results 61 to 70 of about 52,439 (271)

Trace element geochemistry of peridotites from the Izu-Bonin-Mariana Forearc, Leg 125

open access: yes, 1992
Trace element analyses (first-series transition elements, Ti, Rb, Sr, Zr, Y, Nb, and REE) were carried out on whole rocks and minerals from 10 peridotite samples from both Conical Seamount in the Mariana forearc and Torishima Forearc Seamount in the Izu ...
Ingram, G.   +4 more
core   +1 more source

A mutli-technique search for the most primitive CO chondrites [PDF]

open access: yes, 2018
As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined: (
Alexander   +68 more
core   +1 more source

The nature and formation of silica minerals in eucrite meteorites: Insight into the protoplanetary magma crystallization

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Silica polymorphs in meteorites provide critical constraints on crystallization processes associated with thermal activity in the early solar system. A detailed investigation of silica polymorphs in eucrites (the largest group of achondrites) using cathodoluminescence imaging and laser‐Raman spectroscopy revealed significant variations in the ...
Rei Kanemaru   +14 more
wiley   +1 more source

Formation, preservation and extinction of high-pressure minerals in meteorites: temperature effects in shock metamorphism and shock classification

open access: yesProgress in Earth and Planetary Science, 2022
The goal of classifying shock metamorphic features in meteorites is to estimate the corresponding shock pressure conditions. However, the temperature variability of shock metamorphism is equally important and can result in a diverse and heterogeneous set
Jinping Hu, Thomas G. Sharp
doaj   +1 more source

Testing the ureilite projectile hypothesis for the El'gygytgyn impact: determination of siderophile element abundances and Os isotope ratios in ICDP drill core samples and melt rocks [PDF]

open access: yes, 2013
The geochemical nature of the impactites from International Continental Scientific Drilling Project-El'gygytgyn lake drill core 1C is compared with that of impact melt rock fragments collected near the western rim of the structure and literature data ...
Abe   +94 more
core   +1 more source

High-temperature water–rock interactions and hydrothermal environments in the chondrite-like core of Enceladus

open access: yesNature Communications, 2015
It has been suggested that Saturn’s moon Enceladus possesses a subsurface ocean. The recent discovery of silica nanoparticles derived from Enceladus shows the presence of ongoing hydrothermal reactions in the interior.
Y. Sekine   +11 more
semanticscholar   +1 more source

Investigation and reclassification of four mesosiderites—Implications for their formation

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Mesosiderites are rare, differentiated meteorites, so‐called stony‐iron meteorites—they are impact breccias composed of an unusual mix of crustal basalt and pyroxenite, core‐derived metal, but no mantle materials. This odd mixture makes their origin enigmatic and has inspired many different formation theories over the last several decades ...
Gabriel Zachén   +4 more
wiley   +1 more source

Mineralogy and geochemistry of rare earth elements in the Moyil Valley alteration zones, Meshkinshahr (northwest Iran)

open access: yesGeologos, 2020
Sabalan Mountain (northwest Iran) witnessed intense volcanic activity during the Cenozoic (Plio-Pleistocene). The result of this manifests itself in the conical geometry of the Sabalan stratovolcano and ahigh hydrothermal gradient around it, which can be
Naseri Hossain   +3 more
doaj   +1 more source

The Origins of I-type Spherules and the Atmospheric Entry of Iron Micrometeoroids. [PDF]

open access: yes, 2016
The Earth's extraterrestrial dust flux includes a wide variety of dust particles that include FeNi metallic grains. During their atmospheric entry iron micrometeoroids melt and oxidize to form cosmic spherules termed I-type spherules. These particles are
Genge, MJ
core   +1 more source

Petrography of phosphates in CI and CY carbonaceous chondrites

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Phosphate minerals are significant carriers of volatiles (e.g., OH) and halogens in chondritic material; however, their origin in most groups of carbonaceous chondrites remains poorly characterized. We have determined the abundance, morphology, texture, and composition of phosphate grains in aqueously altered CI chondrites and in hydrated and ...
C. S. Harrison   +3 more
wiley   +1 more source

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