geography Soil physical and chemical

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geography Soil physical and chemical
2010-10-11 21:57:50
geogrpahy soil

geog soil physical and chem
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  1. Define Weathering
    All physical and chemical changes produced in rocks, at or near the earths surface, by atmospheric agents.
  2. What happens to primary minerals in weathering
    Primary materials are broken down into secondary minerals
  3. What are the three primary rocks that are broken down via weathering
    • Igneous
    • sedimentary
    • metamorphic
  4. What is ment by disintegration and decomposition in regards to the three rock types
    • Disintegration is a physical breakdown of rocks into minerals
    • Decomposition is the chemical breakdown of rocks into minerals
  5. After disintegraion what are two exapmples of minerals that are very slowly weatherd
    • Quartz
    • Muscovite
  6. After disintegration what is an example of two minerals that are Slowly Weathered
    • Feldspar
    • Biotite
  7. After disintegration what are three examples of minerals that are easily weatehered
    • Calcite
    • Augite
    • Hornblende
  8. What happens to Quartz and Muscovite after continued disintegration
    They become Resistant primary minerals
  9. What happens to Quartz and Muscovite after Alteration (Both phsycail and chemical)
    Quartz and Muscovite become Silicate Clays
  10. What happens to feldspar and biotite after Decomposition and Recombination
    They will become other Silicate Clays
  11. What happens to Calcite Augite and Hornblende After decompoisiton oxidation and hydration
    • Oxides of
    • Fe
    • Al
  12. What can happen to Calcite, Augite and Hornblende when decmoposed
    These can be decomposed into an aqeuous solution
  13. What happens to the three rock types after decomposition
    Decomposition leads to the dissolvment of these three into an aqeuous solution
  14. What three alternatives can the three rock types in aqueous solution become
    • Organic acid solution
    • Hydrolysis
    • Solution
  15. What becomes of the three rock types after they become an organic acid solution
    • They form organic complexes of Al3+ and
    • Fe3+
  16. What do the three rock types become after hydrolysis
    Silicic acid
  17. What happens to the three rock types if they remain in solution
    • They become soluble materials such as
    • Ca
    • Mg
    • K
    • Na
    • Fe
    • SO4
  18. What are the three types of Phsycial (AKA mechanical) Weatehring or disintegration
    • Temperature
    • Abrasion
    • Plants and Animals
  19. What is ment by abrasion
    Abrasion can be caused by the sand paper effect of sediments trapped in either water ice or in the wind which can then act to grind down pre existing rocks
  20. How much affect to plants and animals have on the disintegration of rocks
    Plants and Animals have a minimal effect on the breakdown of rocks
  21. Besides physical weathering what other type of weathering is there?
    • Chemical weathering AKA
    • Biogeochemical weathering
    • AKA
    • Decomposition
  22. What three things enhances the effects of chemical weathering
    • Geological
    • Biological
    • Plant
  23. What is ment by geological chemical weatehring
    Water and ocygen acts to decompose rocks
  24. What is ment by biological chemical weathering
    Microorganisms can create acids
  25. What is ment by plants chemical weathering
    Plant root metabolism which i assume removes and adds CO2 i guess
  26. What is ment by Biogeochemical weathering
    • Biogeochemical weatehring incorporates all of:
    • Geological
    • Biological
    • Plant
    • Chemical weathering
  27. Define Hydration in relation to Biogeochemical Weathering
    Hydration - intact water molecule binds to a mineral
  28. Define Hydrolysis in biogeochemical weathering
    Hydrolysis - Water reacts with a mineral with H+ Replacing a cation
  29. Define Dissolution in regards to biogeochemical weathering
    Dissolution - Water dissolves minerals by dissolving ions
  30. Define Carbonation and other acid reactions in regards to biogeochemical weathering
    Acids will accelerate the effects of weathering
  31. Define Oxidation and Reduction in relation to Biogeochemical weathering
    The loss or gain of electrons in relation to oxygen availability
  32. Do weatehring proccess act alone?
    No weathering proccess work together
  33. What does physical weathering do to increase biogeochemical weathering
    Physical weathering disintegrates rocks which leads to an increased surface area for biogeochemical weathering to act on.
  34. Give an example of how biogeochemical weathering acts together
    Hydrolysis can release Fe, Mn which can then be oxidized or reduced
  35. What cna soil colour say about a soil
    Soil colour can give an idea of mineral content, movement of nutrients through soil as well as water content
  36. What is soil colour affected by
    • Organc matter content
    • Water content
    • Presence of Fe Mn
  37. Waht colour of soil would iron oxides produce
    Red Brown Grey Blue
  38. What colour of soil would we expect Manganese oxide to be
  39. What colour fo soil would we expect Gluconite to be
  40. What clour of soil would we expect Calcite to be
  41. Give an example of a Munsell Colour Chart Number
    7.5YR 6/4
  42. Of 7.5YR 6/4 what represents Hue
    Hue is the first value or 7.5 YR
  43. Of 7.5 YR 6/4 What represents Value
    the Number 6 represents the Value number
  44. Of 7.5YR 6/4 what does the 4 represent
    the 4 is the Chroma
  45. What is ment by Hue
    Hue is a general colour range, Red, green yellow etc.
  46. Waht range can Value have? What does each extreme of the range represent
    • Value is measured 0 - 10.
    • 0 = pure Black
    • 10 = Pure White
  47. What range is Chroma
    • Chroma
    • 0-10
  48. Soil Colour--------
  49. What does a brown to black say about a soils attrbutes
    A brown to Black says a high amount of organic material is present
  50. What does a black subsurface horizon represent
    A Subsurface horizon of Black indicates a Manganese parent material such as basalt is present
  51. What does bright-light soil colour represent
    The Eluvial horizon is present
  52. What does it mean in the environment when the E horizon is showing
    • A showing E horizon means that an environment in which
    • precipitation > evapotransperation
    • meaning a leaching of sequoxides has occured
    • the E horizon is consisting mainly of Silica
  53. What does a soil colour of yellow to redish suggest
    • Fe3+ is present in the soil
    • this occurs in well aerated soils
  54. What does a gray greenish blue soil mean
    • Gray greenish blue is indicitive of a
    • Fe2+ presence
  55. What environment does a grey greenish blue soil (Fe2+) occur in?
    Poorly drained soils
  56. What does a white to gray soil colour represent
    White to grey is the accumulation of salts
  57. What parent material would cause a white to gray soil colour
    • Marl
    • Quartz
  58. Name from smallest to largest
    Clay Sand Silt
    • Clay 0.002 mm
    • silt 0.002 - 0.05 mm
    • Sand 0.05 - 2 mm
  59. What does a smaller size mean in realtion to chemical reactions
    A smaller size of soil means a greater surface area on the soil meaning more pore spaces and water holding capacity along with increased surface area for chemical reactions meaning a greater rate of chemical reaction
  60. What five effects does a greater surface area due to smaller particles of soil have
    • 1. Water as thin films greater surface area meaning greater chem rxns
    • 2. Greater Gas retention
    • 3. Faster rate of plant nutrient release
    • 4. Greater attraction for charged minerals
    • 5. microbe reactions
  61. Remerb what u know about sand silt and clay water hlding nutrient holding attraction to eachother size u already know all these things well enough to fill in his chart