Petrographic studies and mineralogical characterization of the Dellen impactites

Abstract The impact origin of the Early Cretaceous (140.82 ± 0.51 Ma) 20‐km diameter Dellen structure was proven in late 60s based on discovery planar deformation features (PDFs) quartz grains. Although decades have passed, impactites found from crater not received much attention. Thus, this study provides a detailed petrological and mineralogical description Dellen. Impactites were classified observations using latest recommendations nomenclature. studied samples include melt rocks (clast rich, clast poor, free), suevitic breccias, shocked unshocked granite, shatter cone. Altogether, 16 with different lithologies polarization microscope. Selected an energy dispersive spectroscopy detector attached to scanning electron microscopy. PDFs indexed four‐axis universal stage seven samples. for PDF studies consisted clast‐rich (DEL10, DEL13, D99), breccias (DEL14, DEL16, DEL24), granite target rock (DEL17). A total 197 sets 113 grains studied, 186 resulted rational crystallographic orientations. Common orientations π{101̅2}, ω{101̅3}, z{101̅1}, ξ{112̅2}, {101̅4}. In rocks, ballen silica plagioclase checkerboard texture abundant. petrographic results indicate range shock pressures at least 2 over 60 GPa, diagnostic metamorphic minerals occurrence rock.