Question

9.2.5 quiz: weathering and erosion
which type of weathering occurs as water falls down iguazu falls?
a. breaking apart by plants and animals
b. abrasion
c. ice wedging
d. cracks from temperature changes

Explanation:

Abrasion is a type of physical weathering where rocks are worn away by friction. In the case of water falling down Iguazu Falls, the force of the water (carrying sediments in some cases) rubs against the rock surfaces, causing abrasion.

• Option A is related to biological weathering (plants and animals), which is not the case here as the question is about water - related weathering.
• Option C (ice wedging) occurs when water freezes in cracks. There is no indication of freezing water in the context of a waterfall.
• Option D (cracks from temperature changes) is thermal expansion - contraction weathering, which is not related to the action of water falling as in a waterfall.

Answer:

B. Abrasion