Olivine Phenocryst

Olivine crystal from 1932 eruption of Quizapu Volcano in Chile

These images were produced using x-ray computed tomography to demonstrate the three dimensional structure and inclusions of volcanic crystals the size of sand grains. Volcanologists use these crystals to study magma movement prior to eruptions. The crystals and magma glass trapped inside them, known as melt inclusions, offer windows into the magma’s chemical history. The crystal’s chemistry teaches us about the temperature of the magma when it grew. Changes to that chemistry can record the mixing of magmas in the volcano’s plumbing system and give estimates of time between mixing during eruptive run-up and the eruption. Additionally, we can measure volatiles (H2O, CO2, S, F, Cl) trapped inside these inclusions to learn about the gases driving the eruption. Diffusive loss of these volatiles from melt embayments and the crystal itself record ascent rates as magmas move up through the volcanic plumbing system.

X-ray computed tomography data was collected at The American Museum of Natural History’s Microscopy and Imaging Facility and processed in collaboration with scientists at Columbia University’s Lamont Doherty Earth Observatory and the University of Nevada, Reno.

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