A large, relatively stable portion of the Earth's crust. Although ocean basins originally were considered low cratons, today the term applies only to continents. Continental (high) cratons are the broad heartlands of continents with subdued topography, encompassing the largest areas of most continents. Cratons experience only broad (epeirogenic) warping and occasional faulting in contrast to the much more structurally mobile or unstable zones of continents, which include mountain ranges, such as the Himalaya, and rift zones, such as those of East Africa. The terminology used today to express these contrasts was first proposed by the German geologist L. Kober in 1921. Kratogen referred to stable continental platforms, and orogen to mountain or orogenic belts. Later authors shortened the former term to kraton or craton. A complementary term, taphrogen, coined in the 1940s, encompasses the rift structures.