Intra-Oceanic Subduction Systems:Tectonic and Magmatic Processes

High-Volume Magmatic Events in Subduction Systems

Subduction-related magmatic arcs represent immense accumulations of intermediate, calc-alkaline igneous rocks and are considered the main factories of continental crust on Earth. Estimating the pace at which these giant volumes of magmatic rock were added to the crust and the mechanisms responsible for magmatic addition are fundamental issues for the disciplines of igneous petrology and contine...

Magmatic Processes : Physicochemical Principles

The viscosities of eight melt compositions in the System albite-H20-F20_1 have been determined at high pressure and temperature. Measurements were performed using the falling sphere method at 1000-1600°C and 2.5 to 22.5 kbar. Fluorine and water strongly decrease the viscosity of albite melt at all pressures and temperatures investigated. The viscosity of a fluorine-bearing albitic melt decrease...

Subduction-zone structure and magmatic processes beneath Costa Rica constrained by local earthquake tomography and petrological modelling

S U M M A R Y A high-quality data set of 3790 earthquakes were simultaneously inverted for hypocentre locations and 3-D P-wave velocities in Costa Rica. Tests with synthetic data and resolution estimates derived from the resolution matrix indicate that the velocity model is well constrained in central Costa Rica to a depth of 70 km; northwestern and southeastern Costa Rica are less well resolve...

Processes of Magma Evolution and Magmatic Suites

Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical Intra-oceanic Arc1

Major element compositions of glass inclusions in olivine and plagioclase phenocrysts from representative Mariana arc lavas show that mafic Mariana arc liquids are tholeiitic and not high-alumina, implying that the high-alumina characteristic of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic melts previously unrecognized among Marian...