Weathering GPH 111 Weathering Game Plan w What

Weathering GPH 111

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

What is Weathering? w 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.

Weathering within Geomorphology Sierra Estrella Mountains and the Gila River

Weathering Processes w Salt Weathering w Sheeting w Solution w Frost Action w Oxidation w Hydrolysis w Thermal Expansion

w Chemical _________ Weathering Processes - 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 w 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 w Extra

Weathering Processes w 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 w 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 w Extra

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

Chemical Weathering w Hydrolysis Minerals chemically combine with water, substituting silica for hydrogen and weathering individual mineral grains This process removes CO 2 from the atmosphere, counteracting global warming Feldspar (K, Al, Si, O) + carbonic acid and water residual clays (Kaolinite) + dissolved minerals + Si

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

Chemical Weathering w Oxidation The Wave, Southern Utah Wupatki, Northern Arizona

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

Chemical Weathering w 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

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

Weathering Landform Caves and Caverns

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

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

Weathering Landform

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

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

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

Physical Weathering

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

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

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

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

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

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

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

Extra Weathering w Root Growth - Root growth extends into rock fractures, expand bust the rock apart

Where do you think the different weathering processes dominate on the planet? w w w 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!!!

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

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

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