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Updated: Nov 21, 2025

Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt
Published on: August 7, 2017
Highly explosive basaltic eruptions driven by CO2 exsolution.
Chelsea M Allison1,2,3, Kurt Roggensack4, Amanda B Clarke4,5
1School of Earth and Space Exploration, Arizona State University, PO Box 876004, Tempe, AZ, 85287-6004, USA. cmalliso@asu.edu.
High carbon dioxide (CO2) and sulfur (S) in basaltic magma, evidenced by melt inclusions, likely drove the explosive Sunset Crater eruption. This suggests CO2 exsolution can trigger powerful basaltic eruptions, impacting the atmosphere.
Area of Science:
- Volcanology
- Geochemistry
- Petrology
Background:
- The 1085 AD Sunset Crater eruption produced unusually high volcanic plumes (>20 km).
- Eruptive mechanisms for this explosive basaltic event remain unclear.
Purpose of the Study:
- Investigate the eruptive mechanisms of the Sunset Crater eruption.
- Analyze melt inclusions to determine magma volatile content and its role in explosivity.
Main Methods:
- Melt inclusion analysis from Sunset Crater samples.
- Raman spectroscopy to determine bubble contents (CO2, S, H2O).
- Modeling of post-entrapment modification and magma storage conditions.
Main Results:
- Melt inclusions show high total CO2 (~6000 ppm) and S (~2000 ppm), with moderate H2O (~1.25 wt%).
- Two distinct melt inclusion groups suggest heterogeneous entrapment of melt and exsolved CO2.
- Evidence for an exsolved CO2 phase at ~15 km magma storage depth.
Conclusions:
- Exsolved CO2 likely drove the explosive basaltic eruption at Sunset Crater.
- This mechanism is analogous to H2O exsolution in silicic caldera-forming eruptions.
- Explosive basaltic eruptions, even if modest in volume, can significantly impact the atmosphere due to their gas composition.
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