Hypervelocity impact of steel into Coconino Sandstone

Abstract

Impact of a 0.4019-g steel sphere at 4.27 km/sec into Coconino Sandstone [Permian] from Meteor Crater, Arizona, produced a crater 11-12 cm across and 2.45 cm deep. The ejecta consist of sandstone fragments, disaggregated sand, splinters of sand grains, strongly shocked aggregates of crushed sandstone grains, and chips, splinters, small amounts of silica glass, and minute spheres of steel. Part of the shocked steel was melted, and some of the melted and unmelted steel occurs as impregnations in the strongly shocked sandstone. Small amounts of glass, which were produced by shock from the sandstone, were found. The fusion of the steel cannot be due to compressive heating alone but can be partly accounted for by conduction of heat from the shocked sandstone and by production of heat by viscous drag and friction along the sandstone-projectile interface and along shear planes in the projectile.