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

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 À1 . Low intensity of broad Raman bands near 495 and 800 cm À1 , 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 À1 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 À1 ) 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.

Non-luminescent nature of the planar deformation features in shocked quartz from the Ries impact structure, Germany: A new interpretation

“…5b). These results may corroborate the observations of Boggs et al (2001) and agree with the conclusions obtained from our Raman spectroscopic observations (Gucsik et al 2011). Alternatively, the non-luminescent nature of PDFs may be due to the absence of traps or recombination centers because of amorphization.…”

“…Götte et al 2011, and references therein). The weaker emission band at 385 nm in quartz grains from Polsingen suggests that these grains suffered relatively higher shock metamorphism than those from Seelbronn, which was further confirmed using micro-Raman spectroscopy (Gucsik et al 2011). However, determining the shock stage in impactites is complicated, as the suevite is composed of various types of impact rocks which indicate heterogeneous shock metamorphic effects, such that the degree of shock recorded is different in each quartz grain in the rock.…”

“…However, these authors were not able to explain the CL behavior of PDFs, in particular, their non-radiative character shown in the CL images. More recently, the shock-induced amorphization in PDFs of quartz samples from the Ries impact structure (at the Polsingen sampling site) was analyzed by micro-Raman spectroscopy (Gucsik et al 2011). They found that Raman intensity exhibits a moderate increase in the range of 230 to 450 cm -1 indicating that PDFs are in-filled by an amorphous phase.…”

Distinction between amorphous and healed planar deformation features in shocked quartz using composite color scanning electron microscope cathodoluminescence (SEM‐CL) imaging

“…Gucsik et al. () and Pittarello et al. () showed promising results using this technique on shocked quartz from the Ries crater and the El'Gygytgyn impact structure, respectively.…”

“…Also Raman spectroscopy (e.g., Gucsik et al. ), EBSD, and other SEM techniques, and chemical analyses like EDX and WDS can provide useful information.…”