5 Written Questions

1. the amount of time greatly influenced the character of soils
2. made up of O, A, E, and B Horizons
3. • Most material removed from E horizon is deposited in B horizon
   • Accumulation of fine grained material enhances water retentively
4. made up of the O and A Horizons
5. • The fewer Silica tetrahedral bonds needed to be broken, the more easily a mineral is chemically weathered.
   • Few bonds (mafic) - more weathered
   • More bonds (felsic) - less weathered

5 Matching Questions

1. Mass wasting:
2. Oxidation
3. A Horizon
4. Soil erosion
5. Plants & Animals and soil formation

1. a • Any reaction where an element loses electrons
   • Often effects iron bearing minerals (i.e. mafic minerals)
   • Causes rust colored weathering of iron bearing rocks
2. b The transfer of rock and soil downslope under the influence of gravity.
3. c Amount of organic activity effects soil fertility (aka biological activity)
4. d • Largely organic
   • Lots of biological activity
   • Still has humus present (up to 30%)
5. e • Rates vary greatly from place to place
   • Caused by the removal of vegetation which holds the soil in place by it's roots
   • Flowing water is responsible for about two-thirds of the soil erosion in the US

5 Multiple Choice Questions

1. • Different lithologies (physical characteristics) weather at different rates
   1. Differential weathering and rate of weathering
   2. Parent material and soil formation
   3. Climate and rate of weathering
   4. Mineral composition and rate of weathering
2. • Reduction in pressure as rocks are exposed by erosion allows rocks to expand
   • Causes outer portions of rocks to break along concentric slabs
   • Can create an exfoliation dome (Enchanted Rock)
   1. Biological activity (mechanical)
   2. Frost wedging (mechanical)
   3. Unloading, "Sheeting" (mechanical)
   4. Solum or "true soil"
3. • Repeated expansion (heating) and contraction (cooling) of a rock causing stress on rock's outer shell
   • This has not been successfully proven in laboratory tests
   1. Erosion
   2. Chemical weathering
   3. Thermal expansion
   4. Soil erosion
4. Source of weathered material that soils develop from
   • Residual Soils: Soils developed from underlying bedrock
   • Transported Soils: Soils developed on (and from) unconsolidated sediments
   1. Climate and soil formation
   2. Parent material and soil formation
   3. Plants & Animals and soil formation
   4. Time and soil formation
5. • Partially altered parent material
   • Still considered regolith and not true soil
   1. O Horizon
   2. E Horizon
   3. C Horizon
   4. A Horizon

5 True/False Questions

1. Erosion → The physical removal of material by mobile agents such as water, wind, ice, or gravity.

   True        False

2. Soil profile → • Rates vary greatly from place to place
   • Caused by the removal of vegetation which holds the soil in place by it's roots
   • Flowing water is responsible for about two-thirds of the soil erosion in the US

   True        False

3. Mechanical weathering → Chemical transformation of rock into one or more new compounds (DECOMPOSITION)

   True        False

4. E Horizon → • Mostly mineral material
   • Eluviation: as water percolates through the soil, smaller particles are washed away by
   • Leaching: Water dissolves soluble material carrying it downward and depleting the E horizon

   True        False

5. Climate and soil formation → Temperature and wetness
   • The hotter and wetter the climate the thicker the soils
   • Effects soil fertility

   True        False