1. Lecture 7, Soil Development GES175, Science of Soils

2. Parent Material  Soil primary secondary primary secondary minerals minerals

3. Transported Agent Deposit gravity ------------- Colluvial water --------------- Alluvial Marine Marine Lacustrine Lacustrine ice ----------------- Glacial (till, moraine) wind ----------------- Eolian Wide diversity within groups 3 Wide diversity within groups

4. Silver Creek Alluvial deposits

5. Flood Plain (First Terrace) Boise Valley Alluvial deposits

6. Boise Valley First Terrace looking north from second terrace

7. Pleistocene Ice Age 1. Major influence on soil materials 2. Glacial till and moraines (a) highly variable and heterogeneous (a) highly variable and heterogeneous (b) properties reflect source (b) properties reflect source 3. Glacial outwash and lacustrine deposits (a) streams from glacial melt = alluvium (a) streams from glacial melt = alluvium (b) lakes formed, when dried = lacustrine (b) lakes formed, when dried = lacustrine

8. Volcanic ash over alluvium Bonner Series