Origins of Mountains - Mountain Geography: Physical and Human Dimensions - page 23

trenches, and molasse for postorogenic, feldspar-rich terrestrial sandstone deposited in
nonmarine mountain basins (Einsele 2000).
Modern understandings of sedimentary basins that eventually become mountains
consider two main divisions: basins that rest on either continental or oceanic litho-
sphere. Within the two classes are subclasses based on the tectonic processes that
produced the basins. Further, using newer plate-tectonic terminology, shallow marine
shelves without significant tectonism (miogeoclines) are recognized as passive con-
tinental margins; active continental margins have offshore submarine trenches where
oceanic plates descend into subduction zones, scraping off accretionary wedges and
perhaps including island-arc volcanism, with forearc and backarc sedimentary basins.
Five subclasses of continental basins are recognized, as well as four oceanic basins,
with both modern and ancient examples known throughout the world (Strahler 1998).