It is similar in size to Biblis Patera, is surrounded by younger flows, and has two superposed craters, probably of impact origin. These craters are older than the surrounding plains, and they have intersected the caldera walls and pushed material into the floor of the caldera. This 17O-km diameter volcano differs in form from the volcanoes previously illustrated. The caldera has a wide bench around one side. This bench may represent an early lava lake level before further collapse occurred in the middle of the caldera.
Scarps intersecting the caldera appear to be normal faults rather than graben.
The base of the volcano is covered by younger materials so its original size cannot be determined. The flanks of this ancient, southern hemisphere volcano have been strongly modified and embayed. At the summit is an irregular depression that is continuous with a valley, extending down the outer flanks. Concentric graben surround the summit. The volcano is so degraded that there are no well-defined primary volcanic depositional features to provide clues regarding the nature of the erupted materials.