Gigantic volumes of hot material rising from the deep earth's mantle to the base of the lithosphere have shaped the face of our planet. Provided they have a sufficient volume, they can lead to break-up of continents or cause mass extinction events in certain periods of the Earth's history. So far it was assumed that because of their high temperatures those bodies -- called mantle plumes -- ascend directly from the bottom of the earth's mantle to the lithosphere. Scientists explain possible barriers for the ascent of these mantle plumes and under which conditions the hot material can still reach the surface. In addition, the researchers resolve major conflicts surrounding present model predictions....