Following Constantine's conversion, Alexandre Christoyannopoulos recounts that Christian pacifism and anarchism were submerged for nearly a millennium until the emergence of thinkers such as Francis of Assisi and Petr ChelÄickÃ½.
noun. verb. The definition of a plume is a feather or a group of feathers, or a cloud of material spreading from its source. 1  A large, full feather from an ostrich that you wear in your hat is an example of a plume.
The Plume Model. The idea is straightforward. A mantle plume is a large column of hot rock rising through the mantle. The heat from the plume causes rocks in the lower lithosphere to melt. The largest (and most persistent) mantle plumes are presumed to form where a large volume of mantle rock is heated at the core-mantle boundary, about 1,800 miles below the surface, although smaller plumes may originate elsewhere within the mantle.