The role of post-shock heating by plastic deformation during impact devolatilization of calcite

Abstract

An accurate understanding of the relationship between the impact conditions and the degree of shock-induced thermal metamorphism in meteorites allows the impact environment in the early Solar System to be understood. A recent hydrocode has revealed that impact heating is much higher than previously thought. This is because plastic deformation of the shocked rocks causes further heating during decompression, which is termed post-shock heating. Here we compare impact simulations with laboratory experiments on the impact devolatilization of calcite to investigate whether the post-shock heating is also significant in natural samples. We calculated the mass of CO${}_2$ produced from the calcite, based on thermodynamics. We found that iSALE can reproduce the devolatilization behavior for rocks with the strength of calcite. In contrast, the calculated masses of CO2 at lower rock strengths are systematically smaller than the experimental values. Our results require a reassessment of the interpretation of thermal metamorphism in meteorites.

30 pages, 4 figures, 1 Supporting Information, accepted for publication in Geophysical Research Letters

References in corpus (1)

• Enhancement of impact heating in pressure-strengthened rocks in oblique impacts

Cited by in corpus (4)

• Shock recovery with decaying compressive pulses: Shock effects in calcite (CaCO${}_3$) around the Hugoniot elastic limit
• Effect of impact velocity and angle on deformational heating and post-impact temperature
• Experimentally shock-induced melt veins in basalt: Improving the shock classification of eucrites
• Ryugu's observed volatile loss did not arise from impact heating alone