rift valley

English Thesaurus

1. a valley with steep sides; formed by a rift in the earth's crust (noun.object)

hypernym	:	vale, valley,
definition	:	a long depression in the surface of the land that usually contains a river (noun.object)

instance hyponym	:	great rift valley,
definition	:	( geology) a depression in southwestern Asia and eastern Africa; extends from the valley of the Jordan River to Mozambique; marked by geological faults (noun.object)