are the tops of some mid-ocean ridges split by a steep-sided valley
Such a valley would be called a gorge.
dick in your mouth
Valley
A steep-sided tower of rock is a butte
a deep, steep-sided, narrow river valley
Try Fjord.
A deep narrow steep-sided valley formed by a river in the place where there is little rainfall .
A deep valley with steep sides would be called a gorge or canyon.
are the tops of some mid-ocean ridges split by a steep-sided valley
a long deep gulley, a narrow valley or gorge
A canyon.
a mature river
Pass
ravine
ravine
yes, the mid ocean ridges are a steep sided valley at the center of a mid ocean ridge