ChestertonCC - Geo - Rivers - waterfalls and gorges

Where do waterfalls form?

• upper course

• middle course

• lower course

Waterfalls form where a river flows over an area of stronger rock then weaker rock.

• true

• false

The river erodes the weaker rock _ than the stronger rock. This forms a step.

• faster

• slower

Water hits the bottom of the step, eroding down to form a deep _.

• plunge pool

• overhang

• splash back

• undercutting

Water and rock _ from the plunge pool, eroding the rock behind the falling water.

• overhang

• splash back

• undercutting

• plunge pool

Splash back erodes the rock behind the falling water. What is this called?

• plunge pool

• overhang

• splash back

• undercutting

Undercutting leaves the stronger rock sticking out from the top of the step. What is this called?

• plunge pool

• overhang

• splash back

• undercutting

_ pulls the overhang down into the plunge pool.

• gravity

• friction

• splash back

• gorge

Over hundreds of years, these steps repeat, so the waterfall moves _.

• upstream

• downstream

As the waterfall moves upstream, a steep-sided _ is left where it used to be.

• gravity

• plunge pool

• overhang

• gorge