Pedestal Crater Margin This image shows part of the margin of a pedestal crater. A pedestal crater is a crater with its ejecta standing above the surrounding terrain. These form when an impact crater ejects material which forms a resistant layer. This resistant blanket coats material around the crater, which is thus eroded more slowly than the rest of the region. The result is that both the crater and its ejecta blanket stand above the surroundings.