Weathering

Question 1

Weathering

Answer 1

Breakdown of rock in-situ

Question 2

Energy transfer involved in weathering

Answer 2

Most processes involve energy transfer from Sun as radiation or from rain

Question 3

Mechanical weathering

Answer 3

Breakup of rocks without chemical change

Question 4

Frost shattering

Answer 4

Water in a joint freezes, expands 10%, repeat until fragments break off. 2001: several major rockfalls on England’s S coast

Question 5

Salt crystallisation

Answer 5

Salt water evaporates to leave crystals that grow and exert pressure on rocks and break/corrode it, especially if iron traces

Question 6

Wetting and drying

Answer 6

Clay rich rocks (e.g. shale) expand when wet and contract when dry so break, frequent on coast

Question 7

Biological weathering

Answer 7

Breakdown of rocks by organic activity

Question 8

Roots

Answer 8

Plant roots grow in cracks and widen

Question 9

Acid

Answer 9

Water running through decaying vegetation and organisms secreting acids (e.g. limpets)

Question 10

Burrowing

Answer 10

Puffins and rabbits into cliffs, piddocks into rocks

Question 11

Chemical weathering

Answer 11

Involves a chemical reaction where salts dissolve or results in an easily eroded claylike deposit

Question 12

Carbonation

Answer 12

Rain absorbs CO2 from air and forms weak carbonic acid, then reacts with CaCO3 in rocks (e.g. limestone) to easily dissolved calcium bicarbonate

Question 13

Oxidation

Answer 13

Reaction of rock minerals (e.g. iron) with O2 to form powder more vulnerable to weathering

Question 14

Solution

Answer 14

Dissolving rock minerals e.g. halite

Question 15

Hydrolysis

Answer 15

Mildly acidic water reacts with rock minerals to clays and dissolvable salts, degrading rock to be more susceptible to moving

Question 16

Acid rain

Answer 16

SO2 and NOx react with various minerals, weakening or dissolving them