Weathering

Question 1

Chemical Weathering

Answer 1

Wet, humid conditions. Rocks decay or dissolve as chem composition is altered

Question 2

Mechanical weathering

Answer 2

Areas of extreme temp, Rock is physically broken down into smaller pieces, chem comp NOT altered

Question 3

Biological Weathering

Answer 3

Breakdown of rock by action of plants and animals

Question 4

Factors that affect rate of weathering

Answer 4

• Rock type
• Surface A
• Climate
• Vegetation
• Human Activity

Question 5

Rock type

Answer 5

Rocks containing soft minerals, such as calcite or iron, weather more rapidly than others with hard minerals like quartz

Question 6

Surface Area

Answer 6

Rocks with larger s.a weather faster than smaller s.a

Question 7

Climate

Answer 7

High levels of precipitation and larger temp ranges accelerate w

Question 8

Vegetation

Answer 8

Bare surfaces are weathered faster than surfaces with veg.

Question 9

Human Activity

Answer 9

Pollution speeds up weathering, gases, fossil fuels, acid rain, dissolves minerals

Question 10

Freeze Thaw Action Pt. 1

Answer 10

Mountainous areas, temps fluctuate ^ and ↓ freezing point of 💧, 🏞️ have more precip due to relief rainfall + snowfall.

Question 11

Freeze thaw action Pt. 2

Answer 11

E.g Croagh Patrick
Water gathers in joints of rocks, freezes when temps drop ↓ 🥶. 💦 Becomes 🧊, it’s volume expands approx 9% , widening the joint, daytime, rising temps melt the 🧊. Freeze thaw is repeated, cracks slowly increase, cracks, sharp rocks called scree move downslope under influence of gravity

Question 12

Exfoliation (Onion)

Answer 12

E.g Sahara
Hot desert regions, diurnal temperature range (big diff, day and night) , Sunshine brings very high temps, outer layer gets really hot, expands, no clouds at night, heat escapes, temp drops, cool and contract, repeats and exerts stress eventually causing it to crack, thin layer peels away

Question 13

Salt crystalisation

Answer 13

E.g California Coastline
Dry climates + salt solutions, coastal, salt seep into joint, high temp causes evaporation, leaving crystals behind, crystals expand putting pressure on rock, breaks down, honeycomb effect

Question 14

Pressure Release

Answer 14

E.g Granite in Wicklow
Snow, ice, soil or rock cover underlying layer of rock, then removed,
1. Weathering removed schust and slate in Wicklow lying on granite
2. Pressure exerted on granite released, able to expand
3. Created stresses on the rock which eventually fractured in sheets
4. Over time, rock broke away along line of fractures

Question 15

Processes and Landforms: Denudation

Answer 15

The collective name for the weathering and erosion of rocks on the earth’s surface

Question 16

P & L: Erosion

Answer 16

When rocks are broken down and they’re then transported to new location by agent that broke it down.

Question 17

Underground features formed in karst regions

Answer 17

• Carbonation (Carbonic acid dissolves calcium carbonate)
• Percolation (Calcium bicarbonate moves through joints and B. Planes)
• Evaporation (Water and co2 evaporates)
• Deposition (Calcite is deposited)

Question 18

Stalactites

Answer 18

Grow downwards, calcium bicarbonate and grit solidified

Question 19

Stalagmites

Answer 19

Soluble calcium bicarbonate falls from stalactites, forms stalagmite going upwards

Question 20

Pillars

Answer 20

Columns that form when stalagmites and stalactites grow and join together

Question 21

Curtains

Answer 21

Calcite deposits from continuous narrow structure hanging roof of the cave grow down with age.

Question 22

Caves and caverns

Answer 22

Caves are underground passages, caverns are underground chambers found in karst regions
E.g Aillwee Caves

Question 23

How they’re formed

Answer 23

Erosive action of underground streams, solution, Hydraulic action and abrasion