Structures

Mountain building episodes throughout Colorado’s history created geologic structures that are beautifully exposed across the state. Ancient structures that formed more than a billion years ago can be seen today and attest to the longevity of mountain building activity in Colorado. Young faults that offset 10,000-year-old glacial deposits and present-day earthquakes indicate the continuing rise of the mountains.

Well exposed monocline on the northwest end of the Uncompahgre Plateau

Well exposed monocline on the northwest end of the Uncompahgre Plateau.

When rocks respond to the forces acting in Earth’s crust, they bend and/or break. When strata bend, a joint or fracture is formed. If the rocks move after they break, the fracture becomes a fault. In the faults, folds, and unconformities of Colorado we can look back to see how Earth continually makes and remakes itself. Colorado has every kind of fold and fault known to geologists.

Angular unconformity at Box Canyon in Ouray

Angular unconformity at Box Canyon in Ouray.