1. Weathering
GPH 111

2. Weathering Game Plan:
What is WEATHERING and how does it fit within gemorphology?
Major TYPES of weathering
How does climate affect weathering?

3. What is Weathering?
The collective processes that lead to the surface and sub-surface disintegration and dissolution of rock. The major types include physical, chemical, and biological weathering.

4. Weathering within Geomorphology
Sierra Estrella Mountains
and the Gila River

5. Weathering Processes Salt Weathering Sheeting Solution Frost Action
Oxidation
Hydration
Hydrolysis
Thermal Expansion

6. Weathering Processes Chemical
_________ - Minerals chemically combine with water
_________ - Mineral breakdown through contact with Oxygen (Rust)
_________ - Mineral absorption of water causes swelling and stress
_________ - Mineral dissolution by water
Examples: Spheroidal Weathering, Karst Topography, Gnamma Pits
Physical
_________ - Water freezing induced expansion
_________ - Mineral crystal growth induced expansion
_________ - Pressure released expansion through unloading
_________ - Rapid heating from lightning and fires
Examples - Exfoliation Domes and talus slopes
Extra

7. Weathering Processes Chemical
Hydrolysis - Minerals chemically combine with water
Oxidation - Mineral breakdown through contact with Oxygen (Rust)
Hydration - Mineral absorption of water causes swelling and stress
Solution - Mineral dissolution by water into their ionic form
Examples: Spheroidal Weathering, Karst Topography, Gnamma Pits
Physical
Frost Action - Water freezing induced expansion
Crystallization - Mineral crystal growth induced expansion
Sheeting - Pressure released expansion through unloading
Thermal Expansion - Rapid heating from lightning and fires
Examples - Exfoliation Domes and talus slopes
Extra

8. Chemical Weathering Processes
Hydrolysis
Oxidation
Hydration
Solution
Associated Weathering Landforms
Spheriodal Weathering
Karst Topography
Gnama Pits

9. Chemical Weathering Hydrolysis
This process removes CO2 from the atmosphere, counteracting global warming
Minerals chemically combine with water, substituting silica for hydrogen and weathering individual mineral grains
Feldspar (K, Al, Si, O) + carbonic acid and water residual clays (Kaolinite) + dissolved minerals + Si

10. Chemical Weathering Oxidation
Iron bearing minerals (like biotite) combine with Oxygen to generate oxides and softer clay minerals.
Rusted railway car; that has undergone oxidation

11. Chemical Weathering Oxidation The Wave, Southern Utah
Wupatki, Northern Arizona

12. Chemical Weathering
Hydration - Clay minerals absorb moisture along their cleavage planes, dramatically increasing in volume.

13. Chemical Weathering Solution
Minerals can dissolve into ions with water, like dissolving sugar in coffee
Water is the universal solvent, capable of dissolving at least 57 of the natural elements

14. Weathering Landform
Karst Topography - generated through solution mostly into limestone bedrock

15. Weathering Landform
Caves and Caverns

16. Sinkholes
Karst Topography Can Be Associated with Extensive Damage (Sink Holes)

17. Weathering Landform
Spheroidal Weathering - Chemical weathering attacks all surface areas, rounding sharp edges into spheroid shapes.

18. Weathering Landform

21. Weathering Landform
Gnamma Pits - How do you think these guys form, what chemical weathering processes could affect their growth?

23. Physical Weathering Processes
Frost Action
Salt Weathering
Sheeting
Thermal Expansion
Associated Weathering Landforms
Talus Slopes
Exfoliation Domes

24. Physical Weathering
Frost Action - Where water seeps into rock weaknesses during day, then freezes and expands at night--breaking the rock apart.

25. Physical Weathering

27. Weathering Landform
Chemical weathering rounds rocks--physical weathering generates angular rocks.
Talus Slope - A pile of angular rock fragments

28. Physical Weathering
Crystallization - Where mineral rich water seeps into rock, evaporates, and allows the dissolved solids to crystallize, breaking the rock apart.

29. Physical Weathering
Only non-water related process
Sheeting - Buried rocks are under tremendous pressure and once uncovered, pressure drop sharply and the rocks rebound.
Sandstone
Granite

30. Weathering Landform
Half Dome, CA
Exfoliation Dome - Develop after extensive unloading and sheeting.
Enchanted Rock, Texas

31. Physical Weathering
Thermal Expansion - Rocks dramatically heated by forest fires can explode when water absorbed in the rock flashes to steam.

32. Physical Weathering
Thermal Expansion - Rocks dramatically heated by lightning can explode when water absorbed in the rock flashes to steam.

33. Physical Weathering
Thermal Expansion - Different rates of mineral expansion and water absorption throughout numerous day and night cycles.

34. Extra Weathering
Root Growth - Root growth extends into rock fractures, expand and bust the rock apart

36. Where do you think the different weathering processes dominate on the planet?
In the Amazon (Tropical Rainforest)
Serengeti of Africa (Savanna)
Death Valley (Arid)
Minnesota (Humid Continental)
The Sierras (High Alpine)
Alabama (Humid subtropical)
Make a list for each one!!!

37. Importance of Surface Area
What will weather quicker, one huge boulder or a huge boulder broken down into a bunch of smaller boulders? Why?

38. What does Weathering DO?
The in situ disintegration of rock supplied by tectonic (and isostatic) rock input!

39. Things to Know: What is weathering
Chemical processes round edges, physical processes generate angles
Types of chemical weathering and associated landforms
Types of physical weathering and associated landforms
Importance of SURFACE AREA
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