Folding occurs when layers of rock in the crust buckle due to collisions between tectonic plates. There are two main types of folds: anticlines, where the rock layers buckle upwards in an inverted U-shape, and synclines, where layers buckle downwards in a U-shape. Different kinds of folds form depending on the direction and amount of compressional forces, including symmetrical, asymmetrical, overfolded, recumbent, and overthrust folds. Folding of layers can result in the formation of fold mountains over geologic timescales.

1. Landscape Folding

2. What is folding? Folding is the process whereby two plates collide with each other where some of the layers of rock which make up the crust buckle and form folds. Basically two types of fold Anticline Syncline

3. Anticline Happens when the layers of rocks buckle upwards to look like an inverted ‘U’

5. Syncline Happens when layers of rock buckle downwards to look like a “U”

7. Types of folds Symmetrical fold/simple fold Asymmetrical fold Overfold/Overturned fold Recumbent fold Overthrust fold

8. Anticline and Syncline

9. Symmetrical fold A fold where both limbs are equal in steepness because compression from opposite sides is equal.

10. Asymmetrical fold Happens when one limb is steeper, because compression is greater from one side than the other.

11. Overfold / Overturned Fold Happens when one fold is pushed over the other limb due to increasing compression Both limbs are sloping in the same direction.

12. Recumbent Fold Happens when limbs are nearly parallel to each other. Axis is almost horizontal

13. Overthrust Fold Extremely powerful compressional forces which causes recumbent fold to fracture Upper part of the recumbent fold thrust forward along the plane of fracture

14. Different folds Symmetrical fold Asymmetrical fold Overfold Recumbent fold

15. Resultant landforms Fold Mountains. How are fold mountains formed?