Results 51 to 60 of about 7,709 (174)

The Missing Magmas of MOR: Insights From Phase Equilibrium Experiments on Plagioclase Ultraphyric Basalts

open access: yesGeochemistry, Geophysics, Geosystems, 2022
Plagioclase ultraphyric basalts (PUBs) are a class of mid‐ocean ridge (MOR) lavas found in a variety of ocean floor environments, are characterized by abundant (15–40 volume %) plagioclase megacrysts and a diverse trace element and isotopic signature ...
Gokce K. Ustunisik   +2 more
doaj   +1 more source

Vanadium Isotopic Compositions of the High‐3He/4He Baffin Island Lavas

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The isotopic composition of vanadium (V) in hotspot lavas provides new insight into the source of deep mantle heterogeneities. We measured V isotopic compositions in Paleogene Baffin Island lavas, which erupted above the Iceland plume head, to constrain the mantle plume source. These lavas have V isotopic compositions that are lighter (−0.96 ± 
Jonas Kaare‐Rasmussen   +4 more
wiley   +1 more source

Petrological variability of recent magmatism at Axial Seamount summit, Juan de Fuca Ridge

open access: yesGeochemistry, Geophysics, Geosystems, 2013
A combined study of mapping, observational, age constraint, and geochemical data at the summit of Axial Seamount, Juan de Fuca Ridge, has revealed its recent petrological history. Multiple basalt types erupted at the summit in a time sequence.
Brian M. Dreyer   +2 more
doaj   +1 more source

Constraining the Permeability and Outer‐Rise Hydration at the Central America Margin

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 8, August 2026.
Abstract Subduction zones are important drivers of Earth's geochemical evolution; the presence of water within the subduction system has substantial implications for geohazards, including the style of seismicity and the volume of magma generated at arc volcanoes.
D. Douglas   +3 more
wiley   +1 more source

Constraints on Noble Gas Variability in OIB and MORB From Non‐Equilibrium Magmatic Degassing Models

open access: yesGeochemistry, Geophysics, Geosystems
Noble gas concentrations in ocean island basalts (OIB) and mid‐ocean ridge basalts (MORB) are affected by degassing processes, obscuring their pre‐eruptive characteristics.
Thomas Williams   +2 more
doaj   +1 more source

Primitive Cretaceous island-arc volcanic rocks in eastern Cuba: the Téneme Formation

open access: yesGeologica Acta, 2006
The Téneme Formation is located in the Mayarí-Cristal ophiolitic massif and represents one of the three Cretaceous volcanic Formations established in northeastern Cuba.
J.A. PROENZA FERNÁNDEZ   +9 more
doaj   +1 more source

Thermochemical Controls on the X, 410, and 660 Discontinuities in the Central Mediterranean

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 8, August 2026.
Abstract The mantle beneath the Central Mediterranean is thermally and compositionally heterogeneous, as indicated by fragmented and locally stagnant slabs in tomographic images and HIMU‐like anorogenic magmatism. Mantle discontinuities are sensitive to both temperature and composition, and thus provide a way to quantify these heterogeneities.
Luciana Bonatto   +4 more
wiley   +1 more source

Triassic MORB magmatism in the southern Mirdita zone (Albania)

open access: yes, 2006
In southern Albania the Mirdita Ophiolitic nappe is characterized by subophiolitic complexes in which remnants of volcanic ophiolite sequences of Triassic age have been identified, either as rare blocks of variable dimension in the Rubik Complex, or as a thin tectonic unit (the Porava Unit), sited immediately under the main ophiolitic masses of the ...
Valerio Bortolotti   +9 more
openaire   +6 more sources

Early–Late Carboniferous Tectonic Evolution of the Northern North China Craton (NE China): Constraints From Zircon Ages, Geochemistry, and Crustal Thickness Modeling

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The tectonic evolution of the northern margin of the North China Craton (NCC) remains controversial. In this study, we obtained zircon U–Pb ages, geochemical data, and Sr–Nd isotopic data for volcanic rocks, and detrital zircon ages for sedimentary rocks from the Yufutun, Tongqigou, and Benxi formations in central‐southern Jilin Province, NE ...
Yunfei Chang   +6 more
wiley   +1 more source

Highly Enriched and Heterogeneous Mantle Signals Recorded in Mantle Pyroxenite Veins

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The Earth's mantle is inherently heterogeneous, reflecting ongoing mantle depletion and crustal recycling driven by plate tectonics. Radiogenic isotopes in oceanic basalts are commonly used to characterize mantle reservoirs, but the full chemical diversity of mantle‐derived melts may be obscured by magma mixing during melt transport and ...
Zhen‐Yu Zhang   +8 more
wiley   +1 more source

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