The geology of Europa

The map units and lineations of Europa are detailed, and the geologic processes, and history, and thick and thin ice models of the satellite are discussed. It is concluded that Europa lacks evidence of a horizontally stratified crust; the geology appears characterized by disruption of the crust and intrusions into an icy shell. The surface consists of plains and mottled terrain, the former being older. Numerous straight and curved lineations, streaks, stripes, and bands cross EuropA's surface on a global and surface scale. Most lineations appear related to fractures in the crust. Five fresh craters in the 10 to 30 km diameter range are visible. The dark spots, stripes, and bands that appear to have replaced sections of the crust suggest that material was transported to the surface from the subjacent silicate lithosphere. The apparent low density of craters superposed on Europa's surface suggests that the surface is about 100 million years old.