Soils And Eroison

Question 1

How is soil formed and what are the controls on soil production?

Answer 1

Soil is formed by the accumulation of unconsolidated, weathered material. The controls include:
~Temperature
~Sun exposure
~Groundwater Chemistry
~Stability of minerals
~Drainage/topography

Question 2

Draw an idealized soil profile and briefly describe each layer.

Answer 2

O: humus (organic material), zone of biogenic activity,
A: mixture of humus and sediment (topsoil),
E: eluviation; sideways or downward movement of dissolved particles by gravity driven fluid flow. (Clay minerals, iron oxides)

B: zone of accumulation; precipitation of material from above that has been filtered.

C: transition zone from slightly weathered to unweathered sediment/bedrock

R: Regolith or bedrock, unaltered base

Question 3

What is a Pedocal soil and where do they form?

Answer 3

Pedocal soils are ones that form in arid climates. The O and A horizons are compressed due to lack of organic materials. Caliche nodules are present

Question 4

Describe a Pedalfer soil and draw a simple sketch.

Answer 4

~B horizon is massive, large zone of accumulation
~form in areas with more moisture and temperate climates
~A over B over C

Question 5

What type of soil typically forms in a wet, tropical setting? Describe its key characteristics.

Answer 5

Laterite Soil:
~Rich in Al and Fe, which gives red colour
~Thick A and B horizons
~Mafic igneous bedrock 
~Thin or absent humus

Question 6

What is a paleosol and what are they useful for?

Answer 6

A paleosol is a soil profile that has been buried by previous depositional events, and is no longer related to current climate or vegetation.
Good for:
~indicators of paleoenvironments
~landscape evolution
~climate research

Question 7

How can a Paleosol be recognized?

Answer 7

~Root casts
~Oxidation colours (red)
~burrows
~Crumbly, hackly texture (Peds and cutans)

Question 8

What are some mechanisms of erosion/transport?

Answer 8

~Wind
~Water: fluvial transport>> ie rivers
~Rock falls: Talus slope
~Landslides
~Tidal Currents 

And more

Question 9

What are some controls on Erosion?

Answer 9

~Slope 
~Climate: controls type of weathering
~Vegetation: slope stability increased
~Lithology
~Flow velocity