Which mechanism causes 'staircase' valley features when glacial cirques truncate a pre-existing stream valley?

💡 Explanation

Differential erosion creates a 'staircase' valley because the varying resistance of rock layers results in uneven removal by glacial action, therefore, steps form along lithological boundaries rather than uniform downcutting due to river erosion.

• Which phenomenon causes poleward heat redistribution from the tropics through atmospheric cells?
• Which outcome occurs when glacial meltwater carries highly pulverized rock?
• Which consequence results when arid region clay deposition exceeds runoff?
• Which seismic consequence primarily occurs when the lower plate melts during subduction under the overriding plate?
• Which risk increases on a newly-formed volcanic island lacking vegetation?
• Which process limits dissolved oxygen level when coastal upwelling reverses direction offshore?