Mount Roraima

Mount Roraima sits at the point where Brazil, Guyana and Venezuela meet, in the Pacaraima Mountains of the Guiana Highlands, and is the archetype of the tepui, a flat-topped tabletop mountain. Its highest point, on the Venezuelan side, reaches 2,810 meters, while a second summit on the Guyana side reaches 2,772 meters, the country's highest point. The mountain is capped by Proterozoic sandstone roughly 1.7 to 2 billion years old, among the oldest exposed rock on Earth, composed of about 98 percent silica and resting on a granite and gneiss base. It once lay beneath younger Mesozoic rock that has since been stripped away by erosion and mountain-building over the past 180 million years, leaving the resistant sandstone standing as a plateau ringed by cliffs 400 to 1,000 meters high. Intense equatorial rainfall dissolves and leaches the sandstone in a pseudo-karst process, which has helped carve the flat summit and its cliff edges into their present form. This entity documents Mount Roraima specifically as a geological formation, an ancient sandstone tepui shaped by long erosion of a ancient sedimentary plateau.