Geology Reference
In-Depth Information
create entire landscapes, such as the Rocky Mountains of western Canada. When rocks
are folded, they crinkle together similar to bunched-up or gathered fabric.
Folds often occur deep in the crust where the rock layers are exposed to high temperat-
ures and pressures. When these rocks are compressed by convergent plate movements,
they respond plastically by crumpling together or folding.
Scientists categorize folded rocks with different terms that describe the nature of the fol-
ded geography:
Monocline:
Monoclines
are the simplest feature of folded rocks, with layers that are
bent only a little.
Anticline:
Anticlines
are folded rock layers that create an arch (see Figure 9-10).
Syncline:
Synclines
are the opposite of anticlines. Synclines are the U-shaped folds
found between anticline folds (see Figure 9-10).
Figure 9-10:
Anticline and syn-
cline features.
Dome:
Domes
are rounded or oval-shaped areas of rock that are lifted slightly in
the center (bulging), creating the appearance of an anticline. After domes are
eroded, they are recognized by the older rocks in the center and younger rocks
around the outside (see Figure 9-11).
