Here’s a clear and complete summary of the folding process:
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FOLDING PROCESS
Definition
Folding is the bending of rock layers due to compressional forces when tectonic plates move towards each other.
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How Folding Happens
1. Deposition of sediments → Over millions of years, sediments accumulate in horizontal layers.
2. Compression begins → Tectonic plate movement exerts horizontal pressure on the layers.
3. Rock layers bend → If rocks are ductile (flexible) and the pressure is gradual, they bend instead of breaking.
4. Fold structures form:
Anticlines → upward arch folds.
Synclines → downward trough folds.
5. Continued compression → Can produce mountain ranges (fold mountains).
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Types of Folds
Simple fold – symmetrical anticline and syncline.
Asymmetrical fold – one limb steeper than the other.
Overfold – one limb pushed over the other.
Recumbent fold – fold on its side.
Nappe – extreme overfold where layers are thrust over long distances.
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Landforms from Folding
Fold mountains (e.g., Himalayas, Alps).
Intermontane basins and plateaus.
Ridges and valleys in fold belts.
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Conditions Favouring Folding
High compressional forces.
Presence of soft, ductile rocks (like shale).
Gradual application of pressure.
High temperatures and pressures deep within the crust.
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If you want, I can also give you a simple diagram + memory trick to remember all types of folds for exams. That would make it stick instantly.