Evidence for shock metamorphism in sandstones from the Libyan Desert Glass strewn field

Microscopic analysis of sandstones from the southern Libyan Desert Glass strewn field reveals a sequence of progressive deformation features, which range from unaffected rock to extreme brecciation. The quartz grains show a wide range of deformation features: crushing and fracturing, undulatory extinction, mosaicism, oriented cleavage, partial isotropization and multiple sets of planar deformation features. This preliminary report provides the first description of these shock indicators, which are typical for hypervelocity impact, in bedrock material that is assumed to be related to the Libyan Desert Glass.