Buchanan, who is buried in Lancaster, has regularly been ranked one of the worst presidents by historians, citing his ambivalence towards the South wanting to secede from the Union prior to the Civil War.
A shield volcano is a type of volcano usually built almost entirely of fluid magma flows. They are named for their large size and low profile, resembling a warrior's shield lying on the ground.
One of the two most important types of volcanoes, shield volcanoes are large and broad and have relatively gentle slopes. Kilauea on the island of Hawaii is good example of a shield volcano.Eruptions on shield volcanoes are far less explosive than those on composite volcanoes.That is because the basalt lava that erupts from shield volcanoes contains less silica, SiO 2, and is therefore less sticky (less viscous) and doesn't plug up the volcano.ruptions on shield volcanoes are far less explosive than those on composite volcanoes. That is because the basalt lava that erupts from shield volcanoes contains less silica, SiO 2, and is therefore less sticky (less viscous) and doesn't plug up the volcano.