1. Folds, descriptive Goals: 1) To understand the basic geometric elements of folds and 2) to classify folds based on their shape.

2. Outline 1.The basics: Synforms and antiforms 2.Geometric elements of folds 3.Classification schemes

3. Synforms and Antiforms Monocline Synform — Includes synclines and synformal anticlines Antiform — Includes anticlines and anticlinal synclines

4. Geometric elements of folds-I Fold profile plane Fold hinge Hinge zone Fold limb

5. Geometric elements of folds-II Inflection point Axial plane Axial trace

6. Simple and complex fold elements

7. Wavelength and amplitude

8. Classification: Orientation of hinge/axial surface

10. Classify Me

14. Classification: Interlimb angle Gentle 180–170° Open 170–90° Tight 90–10° Isoclinal 10–0°

15. Classify Me

18. Classification based on shape Cylindrical folds Chevron or kink folds Cuspate folds Symmetrical vs. Asymmetrical folds

19. Classify Me

21. Symmetrical ??

22. Fold Vergence

23. Vergence ??

24. Classification: Layer thickness Parallel or concentric folds Similar folds

25. Classify Me

28. Dip-isogon classification Class-1A Class-1B (parallel) Class-1C Class-2 (similar) Class-3

29. Parasitic folds

30. What happens in non-similar folds?

31. Disharmonic Folds

33. Map symbols used for folds Anticlines and synclines Overturned anticlines and synclines Plunging folds