2Weathering Game Plan:What is WEATHERING and how does it fit within gemorphology?Major TYPES of weatheringHow does climate affect weathering?
3What 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.
4Weathering within Geomorphology Sierra Estrella Mountainsand the Gila River
5Weathering Processes Salt Weathering Sheeting Solution Frost Action OxidationHydrationHydrolysisThermal Expansion
6Weathering 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 waterExamples: Spheroidal Weathering, Karst Topography, Gnamma PitsPhysical_________ - Water freezing induced expansion_________ - Mineral crystal growth induced expansion_________ - Pressure released expansion through unloading_________ - Rapid heating from lightning and firesExamples - Exfoliation Domes and talus slopesExtra
7Weathering Processes Chemical Hydrolysis - Minerals chemically combine with waterOxidation - Mineral breakdown through contact with Oxygen (Rust)Hydration - Mineral absorption of water causes swelling and stressSolution - Mineral dissolution by water into their ionic formExamples: Spheroidal Weathering, Karst Topography, Gnamma PitsPhysicalFrost Action - Water freezing induced expansionCrystallization - Mineral crystal growth induced expansionSheeting - Pressure released expansion through unloadingThermal Expansion - Rapid heating from lightning and firesExamples - Exfoliation Domes and talus slopesExtra
9Chemical Weathering Hydrolysis This process removes CO2 from the atmosphere, counteracting global warmingMinerals chemically combine with water, substituting silica for hydrogen and weathering individual mineral grainsFeldspar (K, Al, Si, O) + carbonic acid and water residual clays (Kaolinite) + dissolved minerals + Si
10Chemical Weathering Oxidation Iron bearing minerals (like biotite) combine with Oxygen to generate oxides and softer clay minerals.Rusted railway car; that has undergone oxidation
11Chemical Weathering Oxidation The Wave, Southern Utah Wupatki, Northern Arizona
12Chemical WeatheringHydration - Clay minerals absorb moisture along their cleavage planes, dramatically increasing in volume.
13Chemical Weathering Solution Minerals can dissolve into ions with water, like dissolving sugar in coffeeWater is the universal solvent, capable of dissolving at least 57 of the natural elements
14Weathering LandformKarst Topography - generated through solution mostly into limestone bedrock
36Where 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!!!
37Importance of Surface Area What will weather quicker, one huge boulder or a huge boulder broken down into a bunch of smaller boulders? Why?
38What does Weathering DO? The in situ disintegration of rock supplied by tectonic (and isostatic) rock input!
39Things to Know: What is weathering Chemical processes round edges, physical processes generate anglesTypes of chemical weathering and associated landformsTypes of physical weathering and associated landformsImportance of SURFACE AREANeed Help: WM