Planar Deformation Features in Quartz from the Ries Impact Crater: Advanced by Micro-Raman Spectroscopy

Abstract

ABSTRACT Shocked quartz grains from the Ries impact structure containing planar microstructures such as Planar Deformation Features (PDFs) were characterized by using micro-Raman spectroscopy. Raman spectrum of shocked quartz shows several bands with an intense peak at 459 cm−1. Low intensity of broad Raman bands near 495 and 800 cm−1, which indicate the presence of silica glass, were detected in the PDFs. 2D Raman mapping of the shocked quartz grain shows various distribution patterns of the integrated intensity of A1 Raman band at 459 cm−1 and thus reveal a difference of crystallinity in shocked quartz. The shift and peak broadening of Raman bands to a lower wave number (459 cm−1) may be due to the degree of disordering in tetrahedral sites affected by shock pressure. The results show distinct changes of the Raman properties of quartz with shock pressure and point to a possible use of this method for the identification and characterization of Planar Deformation Features in quartz.