As defined by Gilbert (1890), a form of diastrophism that has produced the larger features of the continents and oceans, for example, plateaus and basins, in contrast to the more localized process of orogeny, which has produced mountain chains. Epeirogenic movements are primarily vertical, either upward or downward, and have affected large parts of the continents, not only in the cratons but also in stabilized former orogenic belts, where they have produced most of the present mountainous topography. Some epeirogenic and orogenic structures grade into each other in detail, but most of them contrast strongly. Adj. epeirogenic.