Association reaction in forsterite under shock compression.

Transmission electron microscopic observation of forsterite (Mg(2)SiO(4)) shocked to peak pressures of 78 to 92 gigapascals revealed that forsterite breaks down to an assemblage of MgO plus MgSiO(3) glass. This strongly supports the interpretation that the high-pressure phase of forsterite under shock compression is due to the assemblage of MgSiO(3) perovskite plus MgO.