Which statement is true about folding in sedimentary rock layers?

Question

Downfolds are called synclines.

Upfolds are called synclines.

Symmetrical folds are called monoclines.

Overturned folds have no trough.

Answer 1

The true statement about folding in sedimentary rock layers is:

Downfolds are called synclines.

In geology, a syncline is a type of fold that is characterized by younger layers of rock being found in the center of the fold, while older layers are found on the outside. Upfolds are referred to as anticlines, and symmetrical folds are not called monoclines; instead, monoclines are a specific type of fold where the rock layers are tilted in one direction. Overturned folds do have a trough, but their limbs have been tilted beyond vertical, causing one limb to dip in the opposite direction.