Transcript Slide 1

High in the North in a land called Svithjod there is a mountain.
It is a hundred miles long and a hundred miles high and once
every thousand years a little bird comes to this mountain
to sharpen its beak. When the mountain has thus been worn away
a single day of eternity will have passed.
- Hendrick van Loon (History of Mankind)
Weathering and Soils
Webpage for course (daytime)
Webpage for course (nighttime)
Lecture 8
General History of a Sedimentary Rock
WEATHERING
TRANSPORTATION
DECOMPOSITION
DEPOSITION
LITHIFICATION
What would Presque Isle be like a
thousand years from now?
<http://www.saintandrew.us/standrews-cathedral.html&usg>
<http://www.swansandravens.c
om/photos.html&usg>
Weathering
Mechanical (Physical)
Chemical
Physical (Mechanical) Weathering
Expansion and contraction
Frost Action
Vegetation
Forest / brush fires
Chemical
Hydrolysis
Dissolution
Oxidation
Result of weathering
Spheroidal weathering - exfoliation
<http://belmont.sd62.bc.ca/teacher/geology12/
photos/erosion/spheroidal2.jpg&imgrefurl>
Differential weathering
<https://www.laredo.edu/science/
Geology/Dennis/newtrips.php&usg>
<http://skywalker.cochise.edu/wellerr/
students/bryce-canyon/bryce.htm&usg>
Factors affecting weathering
Location / Climate
Composition of rock
Time
Important product of weathering -
Soils
Typical soil profile
O horizon
A horizon
B horizon
C horizon
R horizon
contrast
Humid
Arid
contrast
Humid – Brazilian rain forest
contrast
Humid –
Arid – Arizona desert
Bauxite
< http://wiki.chemeddl.org/index.php/PTL:Bauxite&usg >
To improve soils
Addition of rocks that will weather
to produce desired nutrients
crushed granite (adds feldspar)
limestone (adds calcium_
bonemeal (phosphate)