Date post: | 18-Jan-2018 |
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Understanding Soil Formation
Parent Materials
•Classified by the way they were moved and scattered.
Parent Materials•Moved by glaciers•Loess - occurred from blowing of soil after
glaciers melted and dried•Most Desirable
•Outwash - occurs during melting; larger items deposited first, smaller items deposited last
•Glacial Till - No layers•Can contain pebbles to boulders
Parent Materials
•Deposited by flooding streams and rivers•Alluvium -
Bottomlands and flood planes
Parent Materials•Bedrock - Shale,
Sandstone, or Limestone •Organic Matter - Usually
swamp vegetation that has accumulated•Known as Peat and
Muck (muck is more decomposed than peat)
Topography•Steepness(degree),
length, shape, direction•Nearly level soils are
generally poorly drained
•Moderate to steep slopes are generally well drained
Time / Weathering•Physical Weathering•Temperature, Water, Wind, •Freeze/Thaw
•Chemical Weathering•Rainwater is mildly acidic•Oxidation
Climate•Rainfall - slowly by surely erodes•Wind wears away at rock•Hot Summer/cold Winter -
Freeze/Thaw•Humid area - more leaching than
dry areas
Organisms•Plants, Insects, Organisms
•Greatest affect on soil formation is the plants that once grew in it•Native Vegetation
•Example: common native vegetation in the Midwest.•Tall Prairie Grass•Prairie Soils
•Deciduous-hardwood forests•Timber Forests
•How is the Midwest different from Northern Utah?
Organisms