a subsea chasm extending along the crest of a mid-ocean ridge, locus of the magma upwellings that accompany seafloor spreading.
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Origin of rift valley
First recorded in 1890–95
Words nearby rift valley
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Example sentences from the Web for rift valley
This great volcanic period was followed by the eruptions of Kibo and some of the larger volcanoes of the rift-valley.
The older group commenced with a series of fissure eruptions along the site of the present rift-valley and parallel with it.
British Dictionary definitions for rift valley
a long narrow valley resulting from the subsidence of land between two parallel faults, often associated with volcanism. The East African Rift Valley is an example
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for rift valley
A long, narrow valley lying between two normal geologic faults. Rift valleys usually form where the Earth's lithosphere has become thin through extension associated with plate-tectonic processes. Unlike river valleys and glacial valleys that form primarily through erosional processes, rift valleys form by the subsidence of the intermediate land as the faults are pulled apart. They are on the order of thousands of kilometers long and wide. See more at normal fault.
The deep undersea valley located along the center of the mid-ocean ridge. It is associated with the crustal thinning and extensional forces that cause magma to upwell onto the ocean floor.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.