Results 51 to 60 of about 1,743 (188)

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

Boron-bearing skarn-magnetite mineralization of the Mingbulak ore field, Eastern Uzbekistan

open access: yesРуды и металлы, 2023
Spatial distribution of skarn-magnetite deposits in the Tien Shan region is closely related to gabbroid magmatism that accompanies wide fault zones bordering the South Tien Shan folded system from the north and south and extending as a latitudinal belt ...
Ezhkov Yu. B.   +3 more
doaj   +1 more source

Mineralogy, mineral chemistry, and redox equilibria in ten aggregate particles from asteroid Bennu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Examination of 10 Bennu aggregate particles has revealed the presence of many phases which taken together can provide constraints on the oxygen fugacity (fO2) of Bennu samples. Phyllosilicates (saponite and serpentine), carbonates, oxides (magnetite, chromite), sulfides (pyrrhotite, pentlandite), phosphate (hydroxyapatite, Na‐Mg‐phosphate ...
K. Righter   +11 more
wiley   +1 more source

Evaluating maturity of organic matter in hydrated C1 and CM‐like clasts and a dehydrated clast within a polymict eucrite and a howardite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Volatile‐rich xenolithic clasts in different types of brecciated meteorites represent unique pristine solar system material. This study investigates the maturity and thermal history of organic matter using Raman spectroscopy and aqueous alteration effects using infrared spectroscopy in the matrix of 15 volatile‐rich clasts (C1 and CM‐like ...
Swarna Prava Das   +7 more
wiley   +1 more source

Mineralogy and Geochemistry of “Laoshan Jade” from Shandong Province, China: Implications for Petrogenesis

open access: yesCrystals, 2022
“Laoshan Jade” is located in the Yangkou area of the Sulu UHP metamorphic belt. This is the first time a systematic research study is performed on its conventional gemological characteristics, mineral compositions, geochemical characteristics, and ...
Xiaomin Yu, Yingxin Liu, Chuqi Cao
doaj   +1 more source

Nanoscale space weathering features in mature lunar soil revealed by TEM and APT

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Space weathering significantly alters the optical, chemical, and structural properties of lunar regolith at micro‐ and nanoscales; yet detailed nanoscale variability within individual soils remains underexplored. Here we apply transmission electron microscopy (TEM) and atom probe tomography to four mineral grains (olivine, ilmenite, and two ...
Jennika Greer   +6 more
wiley   +1 more source

Integration of remote sensing and geochemical analysis of chromite bodies in the Logar Ophiolitic Complex, Southeast Afghanistan

open access: yesKuwait Journal of Science
Chromite, a significant mineral for chromium, is extensively dispersed toward the southeast and east regions of Afghanistan, particularly in Logar Province.
doaj   +1 more source

Chrome spinel compositions as evidence for an Archaean ophiolite in the Kuhmo greenstone belt in Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1994
Investigations into chromite compositions in Archaean ultramafic rocks are rare. Most Archaean ultramafic rocks have undergone a multi-stage history of deformation and metamorphism, and therefore fresh primary chromite is rarely preserved.
J. Liipo   +3 more
doaj   +1 more source

Natural Resources and Political Patronage in Africa: An Ethnicity Level Analysis

open access: yesReview of Development Economics, EarlyView.
ABSTRACT We investigate the effect of resource discoveries on ethnicity‐level political patronage in Africa using a large geospatial dataset of 254 ethnic groups in 15 countries over the period 1960–2004. We find that the first (or single first) resource discovery in a virgin ethnic homeland increases the share of cabinet posts of that ethnicity.
Sambit Bhattacharyya, Nemera Mamo
wiley   +1 more source

Kinetics of carbothermic reduction of synthetic chromite [PDF]

open access: yesJournal of Mining and Metallurgy. Section B: Metallurgy, 2014
In order to optimize the current reduction process of chromite, a good knowledge of reduction mechanism involved is required. The basic component in chromite ore is FeCr2O4, thus, kinetic investigation of synthetic FeCr2O4 with different amount ...
Wang Y., Wang L., Yu J., Chou K.C.
doaj   +1 more source

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