A downthrown, linear, crustal block, bordered lengthways by normal faults The upstanding blocks on either side may have been lowered by erosion It is a structural feature, which may be of considerable length, caused by the relative lowering of a block between two faults or fault zones The faults are commonly high-angle, normal faults which are parallel in their strike direction Half-graben are bounded on only one side by one or more faults and are associated mainly with tilt-block tectonics Graben with a regional extent and topographic expression can also be called rift valleys Compare Horst
(Geology) (1) A depressed tract bounded on at least two sides by faults and generally of considerable length as compared to its width (2) A rather steeply sided valley formed when faulting caused a block-shaped area to drop relative to the surrounding terrain Lake Tahoe, situated on the border between the states of California and Nevada, occupies a graben ADVANCE \x 540
a sunken area between two roughly parallel faults The faults converge toward one another below the surface, so that they look like the letter "V" in cross section Graben are the result of tension in the crust