Evidence for shock metamorphism in sandstones from the Libyan Desert Glassstrewn field

Microscopic analysis of sandstones from the southern Libyan Desert Glass st rewn field reveals a sequence of progressive deformation features, which ra nge from unaffected rock to extreme brecciation. The quartz grains show a w ide range of deformation features: crushing and fracturing, undulatory exti nction, mosaicism, oriented cleavage, partial isotropization and multiple s ets of planar deformation features. This preliminary report provides the fi rst description of these shock indicators, which are typical for hyperveloc ity impact, in bedrock material that is assumed to be related to the Libyan Desert Glass.