2.6 - Why Do Rocks Breakdown?

Question 1

Weathering

Answer 1

Broken down into sub-aerial processes and rock breakdown

Question 2

Rock Breakdown

Answer 2

Mechanical
Chemical
Biological

Question 3

Mechanical Weathering

Answer 3

Use of physical force to break down rocks e.g. freeze thaw weathering or salt crystal formation

Question 4

Freeze Thaw Weathering

Answer 4

Water seeps into crack in rock, when water freezes the rock physically expands, thawing allows more water in until it fulls cracks. The water freezes and individually breaks the rock up

Question 5

Salt Crystal Formation

Answer 5

Common at coast due to salty sea. Seawater penetrates cracks and pores, then evaporates leaving salt crystals that push and cause tension, individual gains breakdown.

Question 6

Biological Weathering

Answer 6

Break down of rock by living organisms

Question 7

Seaweed Acid

Answer 7

Sulphuric acid attacks rock minerals leading to a chemical reaction (chemcial weathering).

Question 8

Oxidation

Answer 8

Chemical reaction, with iron minerals in the rock. Leaves a red/orange rusty colour on the rock (chemical weathering).

Question 9

Carbonation

Answer 9

Slow dissolution of limestone due to rainfall.

Question 10

Hydrolosis

Answer 10

Minerals breakdown to form new clay minerals, because of water.

Question 11

Boring Molluscs

Answer 11

Live on the rocks scraping away to get food, boring a hole in the rock. Holes bored into the rockk, become weak points for weathering points to act.