The Kap Edvard Holm Layered Series forms part of the East Greenland Tertiary Province, and was emplaced at shallow crustal level (at depths corresponding to a pressure of 1-2 kbar) during continental break-up. It consists of two suites: a gabbro suite comprising olivine and oxide gabbros, leucocratic olivine gabbros and anorthosites, and a suite of wehrlites that formed from the intrusion of th...

[1] Magma production at mid-ocean ridges is driven by seafloor spreading and decompression melting of the upper mantle. In the special case of Iceland, mantle melting may have been amplified by ice sheet retreat during the last deglaciation, yielding anomalously high rates of subaerial volcanism. For the remainder of the global mid-ocean ridge system, the ocean may play an analogous role, with ...

This work focuses on the seismic response of a volcano to different magmatic processes with the aim of sheding light on their driving physics as tracked by seismicity. We study seismic time series recorded at basaltic volcanoes and identify generic seismicity patterns characteristic of (i) inter-eruptive, (ii) reservoir feeding, (iii) reservoir leak, and (iv) dyke injection phases of volcanic a...

The Miocene pyroxene andesite lava flows are exposed in southeastern edge of Urumieh Dokhtar Magmatic assemblage in Iran. The hypocrystalline andesite in parts contain conspicuous co-magmatic igneous enclaves which are dark grey and occur mostly as spherical and occasionally as ribbon shapes with some showing chilled margins. Petrographic study shows that the ribbon type enclaves have been form...

[1] Fragmentation of vesicular magma by rapid decompression is one of the most likely triggers for explosive eruptions. In this phenomenon the decompression rate and the viscoelastic nature of magma are considered to be key factors. In order to obtain a clear idea on the effects of these two factors, controlled fragmentation experiments have been conducted. These experiments have three advantag...

The confi guration of subvolcanic magma storage regions exercises a fundamental control on eruptive style and hazard. Such regions can be imaged remotely, using seismic, geodetic, or magnetotelluric methods, although these are far from routine and rarely unambiguous. The textures of erupted volcanic rocks, as quantifi ed through crystal size distributions (CSD), provide spaceand time-integrated...

Theory and observations point to the occurrence of magma ponds or oceans in the early evolution of terrestrial planets and in many early-accreting planetesimals. The apparent ubiquity of melting during giant accretionary impacts suggests that silicate and metallic material may be processed through multiplemagma oceans before reaching solidity in a planet. The processes of magma ocean formation ...

Within the volcanological community there is a growing awareness that many large- to small-scale, point-source eruptive events can be fed by multiple melt bodies rather than from a single magma reservoir. In this study, glass shard major- and trace-element compositions were determined from tephra systematically sampled from the outset of the Puyehue-Cordón Caulle (PCC) eruption (~1 km(3)) in so...

de Fuca Ridge at the "source site" of the 1993 eruption William Menke Lamont−Doherty Earth Observatory of Columbia University, Palisades NY 10964 USA Michael West Lamont−Doherty Earth Observatory of Columbia University, Palisades NY 10964 USA Maya Tolstoy Lamont−Doherty Earth Observatory of Columbia University, Palisades NY 10964 USA (07−December−01) ABSTRACT Seismic imaging reveals a shallow−c...

[1] Models of the early stages of basaltic eruptions beneath temperate glaciers are presented that consider the evolving sizes of volcanic edifices emplaced within subglacial cavities. The cavity size reflects the competing effects of enlargement by melting and closure by downward ductile deformation of the ice roof, which occurs when the cavity pressure is less than glaciostatic due to meltwat...