Anticlines are folds of rock layers that slope upward on both sides of a low point, forming when rocks are compressed by plate tectonic forces and can range in size from a hill to a mountain range. Synclines are folds that slope downward on both sides of a crest, also forming from compression by plate tectonics across scales from cliff sides to entire valleys.

1. Anticlines and Synclines
A fold of rock layers that slope upward on
both sides of a common low point.
Synclines form when rocks are
compressed by plate-tectonic forces. They
can be as small as the side of a cliff or as
large as an entire valley.
A fold of rock layers that slope downward on
both sides of a common crest. Anticlines
form when rocks are compressed by plate-
tectonic forces. They can be as small as a hill
or as large as a mountain range.