Results 181 to 190 of about 1,147,354 (242)

Making magma chambers from mush

Science, 2017
Volcanology Shallow magma chambers either erupt as volcanoes or solidify as intrusive magma bodies. These magma bodies are traditionally considered to be long-lived and dominated by melt. Cashman et al. review the evidence that shallow magma chambers are actually assembled quickly from much larger, crystal-rich transcrustal magmatic systems.
openaire   +2 more sources

Dynamics of magma mixing in partially crystallized magma chambers

2014
The Tertiary Austurhorn intrusive complex in SE Iceland represents an exhumed magma chamber that has recorded an extensive history of magma mixing and mingling. The basal part of the intrusion consists predominantly of granophyres that have been intensively and repeatedly intruded by more mafic magma.
Weidendorfer, Daniel, Mattsson, Hannes B., Ulmer, Peter   +2 more
openaire   +1 more source

Magma mixing and convective compositional layering within the Vesuvius magma chamber

Bulletin of Volcanology, 1991
The pumice-fall deposits of the last two Plinian eruptions of Vesuvius-a.d. 79 “Pompei” and 3700 b.p. “Avellino”-show a marked vertical compositional variation from white phonolite at the base to grey tephritic phonolite at the top. In both Avellino and Pompei sequences a compositional gap separates white from grey pumice.
CIVETTA, LUCIA, Galati R., Santacroce R.
openaire   +2 more sources

The Roles of Heat and Gas in a Mushy Magma Chamber

Journal of Geophysical Research: Solid Earth, 2022
Abstract Crustal magmatic systems likely consist of magmatic reservoirs dominated by crystal mush. Recent studies suggest that the physical processes occurring in crystal mush could alter the response of magmatic reservoirs during volcanic unrest.
openaire   +2 more sources

Magmas and magma chamber evolution, Troodos ophiolite, Cyprus

Geology, 1987
The Troodos ophiolite traditionally has been considered to have formed by constructive processes at an oceanic spreading center. New information on the phase layering and cryptic variation in gabbros and ultramafic cumulates overlying tectonized harzburgites, however, does not support the existence of a large, steady-state, frequently replenished ...
openaire   +1 more source

Vibro-agitation of chambered magma

Journal of Volcanology and Geothermal Research, 2007
Abstract We present the results of a novel set of calculations into the effect of in situ pressure reduction of a crystal-rich, basaltic magma layer by propagating seismic (P) waves. Three stages in the process are identified. Critically, an instability can arise such that a low pressure melt layer develops close to the floor in initially densely ...
M. Davis, M.A. Koenders, N. Petford
openaire   +1 more source

Convection and Macrosegregation in Magma Chambers

1992
Magmas accumulate in large reservoirs where convection occurs, driven by density differences due to fractional crystallization and temperature variations. The observations consist of igneous rocks representing the final crystallized product and volcanic lava series.
S. R. Tait, C. Jaupart
openaire   +1 more source

The fluid dynamics of evolving magma chambers

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1984
Abstract Recent developments in petrology indicate that fluid dynamic effects are of fundamental importance in controlling magma genesis. The forms of convection in magma chambers arise from compositional variations caused by processes such as fractional crystallization, partial melting and contamination, as well as from thermal ...
Robert Stephen John Sparks, Herbert Eric Huppert, John Stewart Turner   +2 more
openaire   +1 more source

Mid‐ocean ridge magma chambers

Journal of Geophysical Research: Solid Earth, 1992
Geophysical evidence precludes the existence of a large, mainly molten magma chamber beneath portions of the East Pacific Rise (EPR). A reasonable model, consistent with these data, involves a thin (tens to hundreds of meters high), narrow (<1–2 km wide) melt lens overlying a zone of crystal mush that is in turn surrounded by a transition zone of ...
John M. Sinton, Robert S. Detrick
openaire   +1 more source

Simulation of Layered Magma Chambers

Journal of Geological Education, 1991
The principles of magma addition and liquid layering in magma chambers can be simply demonstrated in the laboratory by dissolving colored crystals. The concepts of density stratification and apparent lack of mixing of miscible liquids is convincingly illustrated with hydrous solutions at room temperature.
openaire   +1 more source