factors affecting weathering

Question 1

presence of joints

Answer 1

allows water to seep into rocks and causes frost action or solution carbonation hydrolysis hydration
tree roots pry open rock joints and split into smaller pieces thus exposing deep rock surfaces to elements

Question 2

mineral composition and particle size

Answer 2

quartz are more resistant to chemical weathering than pyroxene and feldspar
therefore granite containing larger amounts of quarts more resistant to chemical weathering than basalt
basalt contains more pyroxene
if rock
if rock is coarse grains and different minerals
granular disintegration occurs instead
dark coloured minerals in rock expand and contract faster than lighter coloured ones
different rates of contraction leading to rock breaking down into constituent grains

Question 3

climatic conditions

Answer 3

temperature and rainfall
physical weathering occurs most when temperatures are near freezing point
chemical weathering occurs most where high temeratures and rainfall like hydrolysis and solution weathering
high temperatures promote chemical weathering as rate of chemical weathering doubles for every 10 degree c increase in temperature

Question 4

where is chemical weathering dominant

Answer 4

in wet tropical regions
allows hydrolysis and hydration to occur actively
abundant plant growth contributes to biological weathering

Question 5

what weathering is dominant in temperate regions

Answer 5

frost action
rate of evaporation is reduced to low temperatures and less rainfall
keeps rocks constantly moist and allows hyrdrolysis to work better

Question 6

what happens to solubility of carbion dioxide in water at 0 degrees C

Answer 6

doubles allowing for stronger carbonation to take place

Question 7

what weathering is dominant in arid regions

Answer 7

rocks disintegrate mainly by alternate expansion and contraction as well as salt crystal growth
chemical weathering occurs with occasional rainfall which allows water to seep into cracks in rocks