1. Lecture 4a Soil Forming Factors
* Parent Material
* Climate
Vegetation
Topography
Time
Soils vary from place to place because the intensity of the factors is different at different locations.

2. Soil Parent Materials
Residual - Soil formed from Bedrock. In Minnesota only the following are close enough to the surface to have a soil formed from them:
Sandstone
Limestone
Basalt
Granite

3. Basalt & Gabbro Transported PM Soils Residual Soils Limestone Granite
Sandstone
Limestone

4. Transported Parent Materials
Water - Rivers = Alluvium
Wind - eolian = sand or silt (loess)
Gravity = colluvium
Ice = Glacial Drift - all materials transported by ice or as a result of glacial activity
alluvium

5. A. Unsorted Glacial Materials
Glacial Till = unsorted deposits left by the retreating ice - made of : sand, silt ,clay, gravel, boulders, stones and large rocks. Till can be deposited into various shapes
Moraines- ground moraine - gently rolling plain
End moraine - large hill or series of hills
Drumlins - low hill shaped by the ice

6. Anatomy of a Glacier Steve Dutch- Natural and Applied Sciences, University of Wisconsin-Green Bay

7. Sorted Parent Materials
Water
Outwash - often stratified sand or sand and gravel
Lacustrine - lake deposited - silt or clay in texture - fine sediments - flat terrain, former lake bottom
Lake Plain
Beach Ridge

8. Wind Loess - wind blown silt (.05 - .002mm diameter)
Sand - dune sand - wind blown sand (eolian sand)

9. Dyad – Where have you seen evidence of glaciers …. One for each person..
VIDEO OF GLACIERS

10. Soil forming Factors Parent Material Climate Vegetation Topography
Time
Soils vary from place to place because the intensity of the factors is different at different locations.

11. Soil Forming Factor - Climate
Temperature - Warmer = Faster Cooler = Slower --> Soil Development
Precipitation - higher rainfall = greater leaching
Leaching Zone - determined by location of CaCO3 in the soil profile
Leaching Index = Pcpt. - Evapotranspiration= the amount of effective rainfall that can cause soil leaching

12. Temperature & Precipitation vs. Clay, Depth to Carbonates & OM

13. Sandstone Bedrock - a residual parent material
The End
Sandstone Bedrock - a residual parent material