graben

1. (geology) An elongated block of the Earth's crust, bounded by faults, that has dropped relative to the surrounding area.Examples: "1959, Robert G. Yates, George A. Thompson, Geology and Quicksilver Deposits of the Terlingua District, Texas, U. S. Geological Survey, Professional Paper 312, page 49, The magnitude and shape of the large grabens strongly suggest that, when they formed, material much more mobile than ordinary rocks was present at a depth no greater than a few miles."; "This system includes the Syrian and Lebanese grabens; the grabens of the Dead Sea, Wadi al Arabah, Gulfs of Aqaba and Suez, Red Sea, and Gulf of Aden; and the Ethiopian graben."; "1997, Jean-Marie Rouchy, 2: Paleogene Continental Rift System of Western Europe, Georges Busson, B. Charlotte Schreiber (editors), Sedimentary Deposition in Rift and Foreland Basins in France and Spain (Paleogene and Lower Neogene), page 83, Migration of the subsidence axis has been revealed by the detailed sedimentological studies in most of these grabens, particularly in the Bresse basin (Curial 1986; Moretto 1986/1987) and in Manosque-Forcalquier."Antonyms: horst