4) Weathering

Question 0

Types of chemical weather and examples

Answer 0

• dissolution by water
• dissolution by acid (calcite+carbonic acid = bicarbonate)
• oxidation (magnetite+oxygen = hematite)
• hydrolysis (olivine+water+oxygen = goethite)

Question 1

Agents of mechanical weathering

Answer 1

• running water (streams)
• wind
• glaciers and ice
• ocean currents and waves
• gravity

Question 2

Clays

Answer 2

Good properties:
-filter toxic metals (Hg, Cd, Pb, U)
-material for pottery
Bad properties:
-swelling of soils
-soil failures (slumps/landslide)

Question 3

Factors that control rate of weathering

Answer 3

1) composition of minerals
2) temperature (high temp increases rate of weathering)
3) presence of water (humidity)

Question 4

Weathering, chemical comp of mineral

Answer 4

• ferromagnesian silicate weather the fastest
• K-Al silicates are more resistant to weathering
• halides and Sulfates dissolve easily in solutions
• carbonate dissolve easily in acidic solutions