The outer perimeter is a circular inward scarp about in diameter on the largely undisturbed Cretaceous and upper Silurian sediments of the Parnaíba basin, breached on the west, north, and south sides by drainage valleys. Within the perimeter there is a series of concentric circular valleys and a central basin, all at roughly the same elevation, separated by ring walls. Shuttle Radar Topography Mission imagery shows a faint ring about in diameter, a second ring of gentle hills about in diameter, and an inner ring of steeper hills, about in diameter and up to high, open to the northwest, surrounding a central basin about in diameter.