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.
Composite volcanoes (also called stratovolcanoes) are much more explosive than shield volcanoes, the other important type of volcano. The large and generally cone-shaped volcanoes form along plate boundaries called subduction zones where one of the Earth's plates moves below another.omposite volcano magma contains more silica, SiO 2, than that of a shield volcano and is therefore stickier (more viscous). This stickiness plugs up the volcano, causing pressure to build-up.