One of the keys to understanding the dynamics of plate interiors is the puzzle of plateau uplifts, especially those isolated from active mountain belts. These are of particular interest because they apparently involve deeply rooted processes and are independent of active subduction. Some of these areas are capped by young alkaline volcanics, while some are free of volcanics. Putorana in Siberia, the Adirondacks and Black Hills of North America, and the Serra do Mar in Brazil are typical cases—irregular areas 100–200 km in diameter, 1 km above their surroundings. Volcanic-capped uplifts are common in Africa (Ahaggar, Tibesti, Jos Plateau, Ngaoundéré, and the Cameroon Zone), as are examples of the volcanic-free uplifts (Fouta Djallon, Angola, Adamawa, and high Veldt). The Colorado Plateau may be similar to volcanic-capped African uplifts.