This aerial view looks west over the 250-meter-deep circular lake that fills the New Quebec Crater, a relatively large, well-preserved crater. The interior topography of the crater is covered by lake sediments that inhibit a determination of whether the structure has a small central uplift. The rocks involved in this impact event are ancient and strongly deformed gneisses of the Precambrian shield. The jumbled and outwardly tilted rocks comprising the rim extend as much as 160 meters above the surrounding countryside, based on its morphological similarity to Meteor Crater in Arizona (slide #10). This was confirmed much later when diagnostic evidence of shock metamorphism was discovered in the minerals from gneiss samples collected from within the crater. Whereas the ejecta blanket has been removed by erosion, some isolated melt rocks have been found up to 2 kilometers from the crater rim.