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Petrology and Marine Geology

Enlarged view: 3D-reconstruction of magma
Image: M. Pistone

This is a 3D-reconstruction of magma containing CO2-rich bubbles (in yellow). The magma was experimentally deformed at relatively high temperature and pressure conditions. Such data give evidence on the behaviour of very viscous magmas for example before a volcanic eruption (image width: 0.006 mm).

Banded obsidians are characterized by continuous layering of pure glass (black bands) and vesicle-rich planes (grey bands). The vesicle-rich layers are generated by deformation and coalescence of gas bubbles during the lava flow.

The top image shows how such deformed gas bubbles look like in a frozen magma, which in this case has been deformed during an experiment (the gas bubbles of the rock sample are shown in yellow). From these data, the flow properties of magmas can be studied.

Enlarged view: Banded obsidian
Image: M. Pistone

Example of banded obsidian of dacitic composition from Big Glass Mountain (California, USA).

Image of the Marine Geology and Geochemistry Group

Petrology studies the formation of rocks. Howsoever a rock is formed, during mountain building or on the ocean floor, its composition reflects the conditions at which it was formed and the time it needed to develop.

Marine Geology and Geochemistry at ETH Zurich
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