Mapas topográficos Potomac

Altitud media: 84 m

The rocks of the falls date to the late Precambrian and are about 750 million years old. The rocks are a resistant metamorphized schist, gneisses, metagraywackes, and metaconglomerates. The Falls formed the last time sea level dropped, during the Last Glacial Period about 35,000 years ago, causing the Potomac…

Altitud media: 73 m

Altitud media: 82 m