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arXiv · 1801.01100

Effects of friction and plastic deformation in shock-comminuted damaged rocks on impact heating

Abstract

Hypervelocity impacts cause significant heating of planetary bodies. Such events are recorded by a reset of 40Ar-36Ar ages and/or impact melts. Here, we investigate the influence of friction and plastic deformation in shock-generated comminuted rocks on the degree of impact heating using the iSALE shock-physics code. We demonstrate that conversion from kinetic to internal energy in the targets with strength occurs during pressure release, and additional heating becomes significant for low-velocity impacts (<10 km/s). This additional heat reduces the impact-velocity thresholds required to heat the targets with the 0.1 projectile mass to temperatures for the onset of Ar loss and melting from 8 and 10 km/s, respectively, for strengthless rocks to 2 and 6 km/s for typical rocks. Our results suggest that the impact conditions required to produce the unique features caused by impact heating span a much wider range than previously thought.

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Kosuke Kurosawa, Hidenori Genda. 2018-01-03. Effects of friction and plastic deformation in shock-comminuted damaged rocks on impact heating. https://doi.org/10.1002/2017gl076285

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