Pyroclastic Shield

A pyroclastic shield is an uncommon type of shield volcano built mainly from pyroclastic material produced by highly explosive eruptions, rather than from the fluid lava flows that build a typical shield volcano. Like other shield volcanoes it has gently sloping flanks, and it frequently develops a central caldera formed by a major explosive eruption, after which lava is often extruded in the later stages of activity. Its explosive eruptions tend to produce only modest Plinian eruption columns compared with other strongly explosive volcano types. Pyroclastic shields occur mainly in the Central Andes of South America and in Melanesia, with additional examples in Africa such as Emi Koussi in Chad.