These structures typically emit an aphanatic liquid in the fashion of a (*) "fountain.
On Venus, the largest one of these structures is found in Alta Regio and is named after the goddess Ma'at. On Mars, some of these structures can be found in the Elysium Province, but the largest one of these structures on Mars is surrounded by a four kilometer tall escarpment. These structures typically emit an aphanatic liquid in the fashion of a (*) "fountain." These structures are formed from seamounts that may accumulate enough material to become a type of island; typically they are built up from layers of basaltic lava. Olympus Mons is one of these mountains. For 10 points, name these broad structures exemplified by Mauna Loa, which are named for a warrior's defensive weapon.
On Venus, the largest one of these structures is found in Alta Regio and is named after the goddess Ma'at.
{shield volcanoes} [Prompt on volcanoes and mountains.]