Flashcards in Waterfalls Deck (7)
What processes cause a waterfall
Differential erosion- as the less resistant rock (limestone) is eroded faster causing a step in the river bed through the processes of hydraulic action and abrasion.
There is predominant vertical erosion due to the high above sea level (high gpe).
How is a waterfall formed
Water flows over a band of more resistant rock (dolerite) overlaying a band of less resistant rock (limestone); the rock becomes undercut and further erosion results in the formation and undercutting of a plunge pool (extended by abrasion). The more resistant rock (dolerite) (once formed a ledge) collapses due to gravity).
Diagram of waterfall
Look in folder
Example of a waterfall
High force river tees England- drops 21 metres. It flows over whinstone and limestone. It is 350m above base level.
What is a waterfall
A cascade of water falling from a height, formed when a river or stream flows over a steep rock face
When is a gorge formed
When a waterfall retreats and forms a gorge ahead of it.