Folds are classified into two main types namely anticlines or up-folds and synclines or down-folds.
Anticline Folds: An anticline is like a geological arch where rock layers are bent upwards. Picture it like a massive ripple in the Earth’s crust, with the limbs of the arch dipping away from each other.
Syncline Fold: Now, think of a syncline as the opposite—a geological trough. Here, the rock layers bend downwards, and the limbs of the trough dip towards each other.
Symmetrical Fold and Asymmetrical Fold: Symmetrical folds are like perfectly balanced arches or troughs, with limbs dipping equally. On the flip side, asymmetrical folds are a bit more dynamic, with one limb dipping at a different angle than the other.
Monocline: Imagine a rock layer taking a sudden bend on just one side. That’s a monocline—a fold where only one limb is involved.
Plunging Fold or Pitching Fold: This fold adds a twist by tilting its axis. Instead of standing straight, it leans at an angle. The inclination of this fold’s axis is called its plunge.
Isocline or Carinate Fold: Isoclines keep things neat and parallel. Both limbs of the fold dip at the same angle in the same direction.
Overturned Fold: In this fold, the limbs are a bit rebellious. They dip unequally in the same direction, creating a tilted effect.
Recumbent Fold: Picture a fold that’s almost lying down on the job—its limbs are bent back almost horizontally.
Zigzag Fold or Chevron Fold: This fold likes sharp angles. Its crest or trough has a distinct zigzag pattern, giving it a chevron-like appearance.
Supratenuous Fold: These folds are all about thickness variation. The crest is thin, and the trough is thick. They form due to complex geological processes like uplift folding and sinking.
Dome Fold or Quaquaversal Fold or Pericline: Picture a rock bed being lifted up in the center, forming a geological dome. When you look at its summit, it’s like an anticline. It’s also known as a compound anticline.
Basin Fold or Centrocline: In contrast, a basin fold is like the Earth’s crust creating a bowl. Rock beds sink in the center, forming a basin. Look at it in a vertical section, and you’ll see a synclinal feature. It’s also known as a compound syncline.
Read Also: Geometry Of A Fold
