High-Voltage Transmission Electron Microscopy Study of Lunar Surface Material

Abstract
The internal substructures of a type B sample have been examined at high magnification and compared with terrestrial rocks. Selected ultrathin sections were prepared from these multiphase materials by an ion-thinning technique and examined in a 1-Mev electron microscope, with complementary optical analyses. The structures in the ilmenite and plagioclase indicate that the lunar material has undergone plastic deformation by dislocation movement and possibly microtwinning, with subsequent recovery. The pyroxene exhibits complex lamellar structures of submicron spacing. These various observations are consistent with the optical microscopy evidence for distortion and recovery and identify the processes involved.