Results 21 to 30 of about 1,474 (181)

A magma ocean origin to divergent redox evolutions of rocky planetary bodies and early atmospheres

open access: yesNature Communications, 2020
Applying first-principles molecular dynamic simulations and thermodynamic modelling, the authors suggest a vertical oxygen fugacity gradient in magma oceans of Earth, Mars, and the Moon.
Jie Deng   +4 more
doaj   +1 more source

CO2‐Undersaturated Melt Inclusions From the South West Indian Ridge Record Surprisingly Uniform Redox Conditions

open access: yesGeochemistry, Geophysics, Geosystems, 2023
The behavior of Fe3+ during mantle partial melting strongly influences the oxidation state of the resulting magmas, with implications for the evolution of the atmosphere's oxidation state.
Yves Moussallam   +7 more
doaj   +1 more source

Disequilibrium Rheology and Crystallization Kinetics of Basalts and Implications for the Phlegrean Volcanic District

open access: yesFrontiers in Earth Science, 2020
Large volcanic eruptions are frequently triggered by the intrusion of hot primitive magma into a more evolved magma-chamber or -mush zone. During intrusion into the cooler mush zone, the basaltic magma undergoes crystallization, which in turn can release
Stephan Kolzenburg   +5 more
doaj   +1 more source

Redox preconditioning deep cratonic lithosphere for kimberlite genesis – evidence from the central Slave Craton

open access: yesScientific Reports, 2017
We present the first oxygen fugacity (fO2) profile through the cratonic lithospheric mantle under the Panda kimberlite (Ekati Diamond Mine) in the Lac de Gras kimberlite field, central Slave Craton, northern Canada.
G. M. Yaxley   +4 more
doaj   +1 more source

The evaluation of physico-chemical parameters of the Nasrand Plutonic complex by using mineral composition

open access: yesJournal of Economic Geology, 2017
Introduction Mineral composition is sensitive to variations in the composition of the magma and can be used to characterize the physical conditions of crystallization such as temperature, pressure, oxygen fugacity and water content.
Fatemeh Sarjoughian
doaj   +1 more source

Mineral chemistry and geothermobarometry of gabbroic dykes ‎of the Garmab Ophiolite sequence ‎‎(Northeast of Kamyaran)‎ [PDF]

open access: yesپترولوژی, 2018
The Garmab ophiolite complex, a part of the Ophiolite-Radiolithic zone of Kermanshah, is located in the northeast of Kamyaran. In view of the Iranian geo-structural zones, this complex is situated between the Sanandaj-Sirjan Zone and the Zagros thrust ...
shahryar Mahmoudi   +2 more
doaj   +1 more source

Upper mantle oxygen fugacity recorded by spinel lherzolites

open access: yesNature, 1986
The oxygen fugacities ( ) recorded by rocks from the Earth's upper mantle have been the subject of much recent study and controversy1–7. Discussion has been stimulated by reported differences of several orders of magnitude between measurements made by different methods (Fig.
Mattioli, G, Wood, B
openaire   +2 more sources

Covariation of Slab Tracers, Volatiles, and Oxidation During Subduction Initiation

open access: yesGeochemistry, Geophysics, Geosystems, 2021
Subduction‐related lavas have higher Fe3+/∑Fe than midocean ridge basalts (MORB). Hypotheses for this offset include imprint from subducting slabs and differentiation in thickened crust.
Maryjo Brounce   +5 more
doaj   +1 more source

Crystallization conditions of two adjacent epidote + diopside-bearing granitic stocks, northeastern Brazil

open access: yesAnais da Academia Brasileira de Ciências, 2021
The Tamboril and Olho d’Água granitic stocks are part of the abundant calc-alkalic magmatic epidote-bearing granitic rocks in the Cachoeirinha–Salgueiro Terrane (CST) in the Transversal Zone Domain, northeastern Brazil. The equigranular Olho d’Água stock
RENAN SIQUEIRA   +2 more
doaj   +1 more source

Oxygen fugacity at the base of the Talkeetna arc, Alaska

open access: yesContributions to Mineralogy and Petrology, 2019
The origin of the more oxidized nature of arc magmas as compared to that of mid-ocean ridge basalts (MORB) is debated, considered to be either a feature of their mantle source, or produced during crustal transit and eruption. Fe3+/FeT ratios (Fe3+/[Fe3+ + Fe2+]) in arc volcanic rocks and glasses and thermodynamic oxybarometry on mantle xenoliths from ...
Claire E. Bucholz, Peter B. Kelemen
openaire   +2 more sources

Home - About - Disclaimer - Privacy