Weathering and Soils Flashcards
Physical weathering
accomplished by physical forces that break rocks into smaller and smaller pieces without changing rock’s mineral composition
Chemical weathering
a chemical transformation of rock into one or more new compounds
Examples of physical weathering
Frost wedging; Biological activity; Unloading
Examples of chemical weathering
Hydrolysis; Dissolution; Oxidation
Hydrolysis
reacts with acid/ water to form clays
Dissolution
carbonate (rock) and acid rain create calcium carbonate solution; Causes sinkholes and caves
Oxidation
rock with O2 or groundwater with Fe is powerful agent that makes rock red
Tropical
Strong chemical
Polar
slight mechanical
Desert
slight mechanical
Mid-latitude
strong chemical and strong mechanical (Michigan)
Differential erosion
Different rock types weather differently; Rocks weather at different rates of weakening due to exposure
Granite
exfoliation; hydrolysis
Basalt
Chemical (oxidation)
Sandstone
granual disintegration
Limestone
dissolution
Shale
granual disintgration into clay
Use of gravel
drains very fast
Use of loam
best for plants; contains lots of organics
Use of silt
oor aeration; compacts easily
Use of Sand
drains fast