questions

Question 1

describe three processes of chemical weathering

Answer 1

Ion exchange - substitution of ions in solution for those held by mineral grains (clays, sheet silicates)

Hydrolysis - reaction between mineral elements & H ion from dissociated water

Solution - atoms are dissolved from a mineral and the atomic structure becomes unstable and is carried off (common minerals, except Fe & Al)

Question 2

What climate is chemical weathering most effective in

Answer 2

humid and high temp environments

Question 3

Explain why hillslopes in arid regions are angular, and hillslopes in humid regions are rounded

Answer 3

humid regions have more precipitation contributing to processes like soil creep and soil wash which create more rounded profiles.

Arid regions weather mainly through mechanical process and are likely to have slides rather than flows resulting in steeper slopes

Question 4

What conditions promote high drainage density and sediment yield

Answer 4

drainage density will increase as resistance or surface permeability decreases.

Sediment Yield:
large basin
high elevation and relief
erosional resistance/rock type
vegetation (lack of)
climate (high temps)

Question 5

Hazards to infrastructure due to processes on deltas

Answer 5

Deltas create unconsolidated materials which pose mass movement hazards if slope becomes too steep or too heavily saturated.

Question 6

describe braided rivers in terms of channel planform, migration, and floodplain stratigraphy

Answer 6

planform: shallow and wide
migration: dominated by lateral accretion and rapid channel formation
stratigraphy: vertically stratified with alternating fine grain to coarse grained deposits