GMPV
Geochemistry, Mineralogy, Petrology & Volcanology

Magma

How do crystal aggregates form in magma chambers?

September 5, 2019
How do crystal aggregates form in magma chambers?
EBSD map of chromite crystals colored according to the orientation, showing random orientations.

By Penny Wieser (PhD student at the University of Cambridge) Clues into the inner workings of volcanoes can be gleamed from material which is erupted at the surface, or that which solidified at depth in the crust. Just before eruption, three main phases are present: a gas phase (containing water, carbon dioxide, sulphur, chlorine etc), a liquid melt phase (the magma), and a solid phase (consisting ...[Read More]

Are mantle melts heterogeneous on a centimeter scale?

July 18, 2019
Are mantle melts heterogeneous on a centimeter scale?

The mantle makes up the majority of the volume of the Earth, but there is still a lot about it that we don’t understand. This is because we can’t observe it directly – forget ‘Journey to the center of the Earth’ – even our deepest drill holes (about 12 km deep) are merely tickling the surface of the planet (about 6400 km to the center). Most of what we know abou ...[Read More]

Building a lava dome: one block at a time

February 7, 2018
Building a lava dome: one block at a time

Lava domes form when lava is extruded from a volcanic vent, but is too viscous to flow far away. Think of thick treacle that does not flow as easily as runny honey, and so when it is extruded, it forms a “lava pile” around the vent. Lava domes commonly form within the crater of a larger volcano (e.g. Mt. St. Helens), but can also stand alone or form part of a “dome complex”. A lava dome can take o ...[Read More]

Living with volcanic gases

January 30, 2018
Living with volcanic gases

Professor Tamsin Mather, a volcanologist in Oxford’s Department of Earth Sciences reflects on her many fieldwork experiences at Masaya volcano in Nicaragua, and what she has learned about how they effect the lives of the people who live around them.  Over the years, fieldwork at Masaya volcano in Nicaragua, has revealed many secrets about how volcanic plumes work and impact the environment, ...[Read More]