Results 71 to 80 of about 27,724 (241)

Sodium partitioning between clinopyroxene and silicate melts

open access: yesJournal of Geophysical Research: Solid Earth, 1995
We present a quantitative model for Na partitioning between clinopyroxene and silicate melt, applicable in the range 0.1 MPa to 6.0 GPa, 1000–2000°C over a wide span of composition. Our model is derived from the Jadeite melting equilibrium, via the relationship ΔGƒ(P,T) = −RTlnKƒ = RTlnD*Na where ΔGƒ(P,T) is the Gibbs free energy of fusion of Jadeite ...
Blundy, JD   +3 more
openaire   +1 more source

Water in Omphacite and Garnet From Pristine Xenolithic Eclogite: T‐X‐fO2 Controls, Retentivity, and Implications for Electrical Conductivity and Deep H2O Recycling

open access: yesGeochemistry, Geophysics, Geosystems, 2023
Kimberlite‐borne eclogite xenoliths having Precambrian oceanic crustal protoliths and entrained from ≥100 km depth can retain pristine geochemical features despite extended residence in the cratonic lithospheric mantle, making them valuable archives of ...
Sonja Aulbach   +5 more
doaj   +1 more source

Frictional experiments of dolerite at intermediate slip rates with controlled temperature: Rate weakening or temperature weakening? [PDF]

open access: yes, 2011
A rotary shear apparatus has been newly set up in Chiba University which can control the temperature near a sliding surface, T_meas, up to 1000°C independently from slip rate, V.
Hirose, Takehiro   +3 more
core  

Progressively Fenitised Schist and Carbonatitic Clasts From a Metasomatic Aureole Beneath the Alkalic Dunedin Volcano, Otago, New Zealand

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Clasts of albite‐porphyroblastic quartzofeldspathic schist, derived from the Otago Schist basement, occur within the Port Chalmers Breccia, a diatreme at the centre of the Dunedin stratovolcano, New Zealand. Schists have undergone varying degrees of replacement reactions (at temperatures of 300° to >500°C) producing hornfelses, with Ca‐ and K‐enriched ...
Alan F. Cooper
wiley   +1 more source

The Lages diatremes: mineral composition and petrological implications

open access: yesAnais da Academia Brasileira de Ciências, 2007
Chemical data of heavy minerals from Lages diatremes in southern Brazil have been studied with the aim of characterizing the sample source(s). Three groups of minerals are recognized: I) aluminian-chromian pyroxene, pyrope garnet and chromian spinel ...
Giancarlo Barabino   +2 more
doaj   +1 more source

Comparative compressibility of clinopyroxenes from mantle nodules

open access: yesEuropean Journal of Mineralogy, 1995
The comparative compressibilities of two clinopyroxenes from mantle nodules were determined by single crystal X-ray diffraction with a Merrill-Bassett diamond anvil cell. The analysed crystals show different chemical compositions: PC 135, from a spinel lherzolitic nodule from Pico Cabugi, NE Brazil, has more R3+ (Fe3+ + VIA1 + Ti + Cr) in the Ml site ...
COMODI, Paola   +3 more
openaire   +3 more sources

Key New Evidence for the Hainan Mantle Plume Head: Ongoing Formation of a Large Igneous Province?

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 5, May 2026.
Abstract The process‐based surface magmatic expression of mantle plumes is typically a large igneous province (LIP) induced by the mantle plume head, followed by subsequent age‐progressive volcanic tracks resulting from plate drifting above the plume tail.
F. Yang   +9 more
wiley   +1 more source

Provenance Reassessment of Eocene Turbidites, New Caledonia: Inferences for Obduction Models

open access: yesGeochemistry, Geophysics, Geosystems
Provenance of pre‐obduction Eocene turbidites from New Caledonia is used to better constrain their geodynamic context and inform debate on subduction polarity.
Dominique Cluzel   +7 more
doaj   +1 more source

Pyroxenites and Megacrysts From Alkaline Melts of the Calatrava Volcanic Field (Central Spain): Inferences From Trace Element Geochemistry and Sr-Nd Isotope Composition

open access: yesFrontiers in Earth Science, 2020
Alkaline volcanic rocks from explosive monogenetic centers often carry an unusual cargo of crystals and rock fragments, which may provide valuable constraints on magma source, ascent and eruption.
Carlos Villaseca   +3 more
doaj   +1 more source

Mineral chemistry of late Variscan gabbros from central Spain: constraints on crystallisation processes and nature of the parental magmas [PDF]

open access: yes, 2015
© 2016. Universidad Complutense de Madrid. The commercial rights of the printed and online versions of Journal of Iberian Geology are property of the Universidad Complutense de Madrid (UCM) and the Consejo Superior de Investigaciones CientÍficas (CSIC),
Jeffries, T   +3 more
core   +3 more sources

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