The vesicular glass from Köfels, Tyrol, contains grains of quartz that have been partially melted but not dissolved in the matrix glass. This phenomenon has been observed in similar glasses formed by friction along a thrust fault and by meteorite impact, but not in volcanic glasses. The explosion of a small nuclear device buried behind a steep slope produced a geologic structure that is a good small-scale model of that at Köfels. Impact of a large meteorite would have an effect analogous to that of a subsurface nuclear explosion and is the probable cause of the Köfels feature.
|Title||Fused rock from Köfels, Tyrol|
|Authors||Daniel J. Milton|
|Publication Subtype||Journal Article|
|Series Title||Tschermaks Mineralogische und Petrographische Mitteilungen|
|Record Source||USGS Publications Warehouse|