Weathering and Landforms Topics

• Introduction
• Weathering
1. Physical Weathering
Frost Action
Exfoliation
Organic Activity
2. Chemical Weathering
Dissolution
Hydrolysis
Oxidation
3. Climate and Weathering
Humid and Warm
Dry and Cold
4. Soil Development
Residual
Colluvial
Alluvial
• Gravity Movements
• Streams
• Groundwater
• Shoreline Waves and Currents
• Wind and Ice
• Landforms in Virginia

Weathering (Part 2)

Physical Weathering (continued)

Exfoliation

• Exfoliation is caused by the expansion of rocks when pressure is released as overlying rocks are eroded away.  Exfoliation creates curved surfaces.

Exfoliation in shales (Photograph by Parvinder Sethi)

Curved slabs of rock have weathered as a result of exfoliation in these Devonian shales exposed in the Valley and Ridge in Highland County.

 

Organic Activity

• Organic activity, or activity by plants and animals, can also cause physical weathering.  Tree roots that grow into crevices and small animals that burrow can cause physical weathering.

Tree roots pushing rocks apart (Photograph by Robert Whisonant)

These tree roots are wedging rocks apart in the Blue Ridge of Botetourt County.  Tree roots along cliff faces or steep slopes can cause rocks to weather out and fall or slide.

 

 

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