Recovery of entire shocked samples in a range of pressure from ~100 GPa to Hugoniot Elastic Limit

TL;DR

This study successfully recovered entire shocked mineral samples across a pressure range from the Hugoniot Elastic Limit (~10 GPa) to melting (~100 GPa), revealing distinct petrographic features and phase boundaries.

Contribution

It presents a novel experimental approach combining laser shock recovery with detailed petrographic and numerical analysis to understand shock effects in minerals.

Findings

Samples show three distinct regions with different optical and microstructural features.

Region I experienced melting, with no crystal features present.

The boundary between regions II and III aligns with the Hugoniot Elastic Limit (~10 GPa).

Abstract

We carried out laser shock experiments and wholly recovered shocked olivine and quartz samples. We investigated the petrographic features based on optical micrographs of sliced samples and found that each recovered sample comprises three regions, I (optically dark), II (opaque) and III (transparent). Scanning electron microscopy combined with electron back-scattered diffraction shows that there are no crystal features in the region I; the materials in the region I have once melted. Moreover, numerical calculations performed with the iSALE shock physics code suggest that the boundary between regions II and III corresponds to Hugoniot Elastic Limit (HEL). Thus, we succeeded in the recovery of the entire shocked samples experienced over a wide range of pressures from HEL (~ 10 GPa) to melting pressure (~ 100 GPa) in a hierarchical order.