This paper reviews the literature on dyking as a mechanism of felsic magma extraction from a source and transport to shallower crustal levels, and review the recent literature suggesting a range of alternative mechanisms of magma migration in hot crustal zones which produce mesoscale pervasive granite sheet intrusions. Recent papers have strongly favoured dyking as the main mechanism controllin...

Viscous heating plays an important role in the dynamics of fluids with strongly temperature-dependent viscosity because of the coupling between the energy and momentum equations. The heat generated by viscous friction produces a local temperature increase near the tube walls with a consequent decrease of the viscosity which may dramatically change the temperature and velocity profiles. These pr...

The Indian Peak volcanic field is representative of the more than 50,000 km3 of ashflow tuff and tens of calderas in the Great Basin that formed during the Oligocene-early Miocene "ignimbrite flareup" in southwestern North America. The field formed about 32 to 27 Ma in the southeastern Great Basin and consists of the centrally positioned I n d i Peak caldera complex and a surrounding blanket of...

In this talk we consider numerical methods to efficiently solve the linear system arising from the discretization of models of coupled magma/mantle dynamics. The model we consider is based on a system of partial differential equations derived by McKenzie [1]. This system describes the creeping flow of high-viscosity mantle matrix and the porous flow of magma, a process which is described by a c...

[1] Thirty interferometric synthetic aperture radar (InSAR) images, spanning various intervals during 1992–2000, document coeruptive and posteruptive deformation of the 1992–1993 eruption on Seguam Island, Alaska. A procedure that combines standard damped least squares inverse methods and collective surfaces, identifies three dominant amorphous clusters of deformation point sources. Predictions...

Liquid water is not stable under current martian surface conditions, but the presence of small gullies on the polewardfacing slopes of midto highlatitude martian surfaces suggests that erosion by liquid water might have occurred. Costard et al. (p. 110) developed a global climate model for Mars when it had a higher obliquity (about 300,000 years ago). Their model shows that more melting of the ...

Banding in obsidian from Big Glass Mountain (BGM), Medicine Lake volcano, California, and Mayor Island (MI), New Zealand, provides a record with a 1/wavenumber power-spectral density and multifractal characteristics. The samples are compositionally homogeneous, with banding defined by variable microlite content (BGM) or vesicularity (MI). In both samples, banding formation is well explained by ...

Recent geochemical studies of MORB genesis suggest that at least some degree of chemical disequilibrium occurs during the transport of magma to the surface. If disequilibrium transport does occur in the mantle, it would seem to preclude melt being distributed in a porous network on grain boundaries that could rapidly re-equilibrate with the solid. The questions remain however, as to how big a m...

[1] Volcanic eruptions are often accompanied by spatiotemporal migration of ground deformation, a consequence of pressure changes within magma reservoirs and pathways. We modeled the propagation of pressure variations through the east rift zone (ERZ) of K ılauea Volcano, Hawai‘i, caused by magma withdrawal during the early eruptive episodes (1983–1985) of the ongoing Pu‘u ‘ O‘ o-Kupaianaha erup...