weathering
Geomorphic Processes
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Definition: Geomorphic processes involve changes in the configuration and arrangement of the Earth's surface.
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Types of Geomorphic Processes:
Exogenic Processes: Modify landforms on the Earth's surface.
Key Processes: Weathering, erosion, transport, and deposition of soil and rocks.
Primary Agents: Water, ice, and wind.
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Gradation Process:
Definition: Leveling of land by natural agents.
Key Agents: Rivers, wind, glaciers.
Components: Weathering, mass wasting, erosion, transportation, and deposition.
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Geomorphic Processes Overview:
Physical Processes: Create and modify landforms.
Types:
Endogenous (Endogenic) Processes: Internal processes that create relief.
Exogenous (Exogenic) Processes: External processes that modify relief.
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A. Endogenous Processes
Definition: Large-scale landform building and transforming processes.
Types:
Igneous Processes:
Volcanism: Volcanic eruptions leading to the formation of volcanoes.
Plutonism: Igneous intrusions.
Tectonic Processes (Diastrophism):
Folding: Formation of anticlines, synclines, and mountains.
Faulting: Creation of rift valleys, grabens, and escarpments.
Lateral Faulting: Strike-slip faults leading to earthquakes.
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Exogenous Processes:
Also known as Gradational Processes.
Components: Degradation and aggradation.
Process Continuum: Weathering → Mass Wasting → Erosion → Transportation → Deposition.
Geomorphic Agents: Gravity, flowing water, moving ice, waves, wind, plants, organisms, animals, and humans.
Degradation Processes: Also called Denudation Processes, including weathering, mass wasting, and erosion.
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Degradation Processes:
Key Components: Weathering, mass wasting, erosion, and transportation.
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Relationship Among Processes:
Weathering, mass wasting, and erosion work together to cause the denudation of the Earth's surface.
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Weathering
Definition: Breaking down or dissolving of rocks and minerals on the Earth's surface.
Processes: Mechanical disintegration and chemical decomposition.
Initiation: Begins in microscopic spaces, cracks, joints, and other rock cavities.
Types of Weathering:
Physical or Mechanical Weathering.
Chemical Weathering.
Biological Weathering.
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Physical or Mechanical Weathering
Definition: Disintegration and decay of rocks without changing their chemical composition.
Key Processes:
Exfoliation: Due to thermal expansion/contraction.
Frost Wedging.
Salt Wedging.
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Chemical Weathering
Definition: Decomposes rocks through chemical changes in minerals.
Key Processes:
Oxidation: Affects iron-rich rocks.
Hydrolysis: Silica in igneous rocks combines with water.
Carbonation and Solution: Carbon dioxide reacts with carbonate rocks.
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Biological Weathering
Definition: Contribution of plants and animals to weathering.
Key Processes:
Roots physically break or wedge rock.
Lichens remove minerals and weaken rock.
Burrowing animals increase weathering.
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Talus Cones: Rock pieces at the bottom of a rock fall.
Landslides: Can cause significant destruction (e.g., a 300-ton boulder blocking a road).
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Case Study: La Conchita Landslide, January 10, 2005.
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Case Study: Monterey Park Debris Flow, 1980.
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Case Study: PCH near Pacific Palisades, November 1956.
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Erosion and Transportation
Geomorphic Agents: Various agents associated with erosion.
Key Agent: Flowing water (Fluvial Morphology).
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Other Agents:
Wind: Eolian Landscapes.
Tides and Waves: Coastal Morphology.
Moving Ice: Glacial