Question

When the land between the cracks sinks a/an ___________ us formed

Answer 1

When the land between the cracks sinks Rift Valley are formed.

Answer 2

${\huge{\mathcal{\red{Rift\:valley}}}}$

A rift valley is formed on a divergent plate boundary when a block of land between two almost parallel faults sinks down.

The Narmada Valley in India, lying between the Satpura and Vindhya ranges, is a rift valley.