Maskelynite formation via solid‐state transformation: Evidence of infrared and X‐ray anisotropy

Abstract

Abstract We present the results of a combined study of shocked labradorite from the Lonar crater, India, using optical microscopy, micro‐Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high‐energy X‐ray total scattering experiments, and micro‐Fourier transform infrared (micro‐FTIR) spectroscopy. We show that maskelynite of shock class 2 is structurally more similar to fused glass than to crystalline plagioclase. However, there are slight but significant differences—preservation of original preimpact igneous zoning, anisotropy at infrared wavelengths, X‐ray anisotropy, and preservation of some intermediate range order—which are all consistent with a solid‐state transformation from plagioclase to maskelynite.