Results 91 to 100 of about 23,398 (258)

The Transition From Melt Accumulation to Eruption Initiation Recorded by Orthopyroxene Fe‐Mg Diffusion Timescales in Late Holocene Rhyolites, South Sister Volcano, Oregon Cascade Range

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 12, December 2025.
Abstract South Sister volcano, Oregon Cascade Range, USA, has repeatedly erupted rhyolite since ca. 40 ka. The youngest such eruptions are the ca. 2 ka Rock Mesa and Devils Chain rhyolites, erupted several hundred years apart from two multi‐vent complexes separated by 3–6 km. Fe‐Mg interdiffusion models of orthopyroxene rims from both rhyolites produce
Nathan L. Andersen, Annika E. Dechert, Dawn C. S. Ruth, May (Mai) Sas, Julie Chouinard, Josef Dufek   +5 more
wiley   +1 more source

Petrography and petrology of the Hawaii Scientific Drilling Project lavas: Inferences from olivine phenocryst abundances and compositions [PDF]

, 1996
The Mauna Loa (ML) and Mauna Kea (MK) lavas recovered by the Hawaii Scientific Drilling Project (HSDP) include aphyric to highly olivine-phyric basalts.
Alves, Sophie, Baker, Michael B., Stolper, Edward M.   +2 more
core   +1 more source

Rapakivi K‐Feldspar Megacrysts in Monzogranitic Porphyry: Evidence for Magma Recharge and Mush Rejuvenation

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 12, December 2025.
Abstract The formation, storage, and evolution of granitic magmas are fundamental processes driving the growth of continental crust. While traditionally attributed to crystal fractionation in high‐melt fraction magma chambers, the model invoking low‐melt fraction crystal mushes has gained wide acceptance.
Wang Li, Xuxuan Ma, Roberto Weinberg, Liang Qiu, Zhiyong Zhu, Haibing Li   +5 more
wiley   +1 more source

Imaging the Shallow Structure Beneath Askja Volcano, Iceland, With Ambient Noise Tomography

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 12, December 2025.
Abstract Askja is a large central volcano in the Northern Volcanic Zone (NVZ) of Iceland which last erupted effusively in 1961 and subsequently experienced steady deflation from the 1970s until August 2021, when GPS and InSAR measurements confirmed that it had begun re‐inflating.
Joseph Fone, Tom Winder, Nicholas Rawlinson, Robert White, Bryndís Brandsdóttir, Heidi Soosalu   +5 more
wiley   +1 more source

Numerical modeling predicts seismic resonances in the magma chamber-conduit system due to wavefield capturing

Volcanica
This study utilizes 3D numerical models to simulate seismic resonances in a volcanic edifice, arising from the interaction between an externally excited wavefield and a magma chamber-conduit system.
Fabian Limberger, Georg Rümpker
doaj   +1 more source

The 1723 AD violent Strombolian and phreatomagatic eruption at Irazu volcano (Costa Rica) [PDF]

, 2013
The largest of the recorded historic eruptions at Irazú volcano began on February 16, 1723 and lasted until at least December 11. We here critically examine deposits of this eruption exposed on the summit of Irazú. Our reconstruction of the eruption is
Alvarado, G. E., Schmincke, Hans-Ulrich
core  

Temperatures of entering magma, formation and dimensions of magma chambers of volcanoes

Bulletin Volcanologique, 1982
A mechanism, of formation of magma chambers that feed volcanoes is discussed. Heat conditions and dimensions of magma chambers which have existed for more than several thousand years may become stable. The approximate equations of heat balance of these chambers are derived by calculating the temperatureT1 of the magma entering chambers and the radiia ...
openaire   +1 more source

Viscosity of Dry and Hydrous Diopside Melts at High Pressures: Implications for Upper Mantle Magma Dynamics

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 12, December 2025.
Abstract Viscosity of silicate melts governs magma transport and influences mantle dynamics, yet effects of pressure and water on melt viscosity remain poorly understood. Here, we report in situ falling‐sphere viscosity measurements on diopside (Di) melts with 0–3 wt.% H2O along the liquidus up to 7 GPa and 2103 K using synchrotron X‐ray radiography ...
Qi Chen, Bin Zhao, Tony Yu, Aaron Wolfgang Ashley, Yanbin Wang   +4 more
wiley   +1 more source

Nakhlite Emplacement as Constrained by X‐Ray Computed Tomography and 3D Quantitative Textural and Petrofabric Analyses

Journal of Geophysical Research: Planets, Volume 130, Issue 12, December 2025.
Abstract Nakhlites, clinopyroxene‐rich rocks, are the largest single‐origin suite of samples from Mars. Despite extensive study to discern their petrogenetic histories, nakhlite emplacement mechanisms and environments are not well‐constrained, and it is unknown whether they represent intrusive or extrusive igneous rocks, or a combination.
Sierra R. Ramsey, Piper Irvin, Arya Udry, Scott A. Eckley, Amanda Ostwald, Richard A. Ketcham   +5 more
wiley   +1 more source

The Pobei Cu-Ni and Fe ore deposits in NW China are comagmatic evolution products: evidence from ore microscopy, zircon U-Pb chronology and geochemistry

Geologica Acta, 2017
The Pobei mafic-ultramafic complex in northwestern China comprises magmatic Cu-Ni sulfide ore deposits coexisting with Fe-Ti oxide deposits. The Poshi, Poyi, and Podong ultramafic intrusions host the Cu-Ni ore. The ultramafic intrusions experienced four
Y.G. LIU, W.Y. LI, X.B. LÜ, Y.H. HUO, B. ZHANG   +4 more
doaj