Question

which process helps in the formation of the rift valley?
(A) seismism
(B) Faulting
(C) Folding
(D) volcanism

Answer 1

HINT: Rift valley is a steep-sided valley formed by the downward displacement of a block of the earth's surface between almost parallel faults or fault systems its typical formation is long, narrow, and deep and are usually found at the bottom of the sea and land.

COMPLETE SOLUTION: A rift valley is formed as a result of a portion of the crust which is skinked into the surface of the earth. 3 steps involved in the formation of the rift valley are -
1. Layers of rocks are subject to stress or tension.
2. Cracks or faults are developed in the layers and the central block begins to subside
After subsidence, a depression with a steep side is formed thus forming a rift valley
The correct answer to this question is b. Faulting, as faulting is a crack in the earth's crust resulted from the displacement of one side with as for the other.
3. The difference between rift valley and block mountain is that block mountain is formed when some part of the earth gets depressed or uplifted and on the other hand, rift valley is formed due to fault or geologic rift.

Therefore, the correct answer to the above question is b. faulting.

ADDITIONAL INFORMATION: The largest and the deepest rift valley is not found on earth but to your surprise, it has been found on mars named Valles Marineris which was formed millions of years ago and is 7 kilometers deep and 4000 kilometers long.

NOTE: A rift valley is formed on a divergent boundary that is spreading a part of the surface or crustal extension, which is subsequently further deepened by the forces of erosion. Many of the rift valleys formed are triple junction or aulacogen.