Exam 20: Mountain Belts and the Continental Crust

Most of the _____ of the United States has/have a very thin blanket - only 1000 to 2000 meters - of sedimentary rock layers.

In some mountain belts the crust breaks into fault-bounded blocks resulting in _____ mountain ranges.

The Grand Canyon, Ozark dome, Black Hills, and Adirondacks expose ________.

Continents grow bigger as _______.

One important result of orogeny is that continental crust becomes thicker.

Orogenies are not accompanied by metamorphism and igneous activity.

According to the concept of ____, lighter less dense continental crust "floats" higher on the mantle than denser oceanic crust.

The once deep-seated roots of former Precambrian mountain belts are the _____ rock for the now stable, central part of the continent.

____, intermixed granitic and metamorphic rock, may represent those parts of mountain belts that were once at even deeper levels of the crust.

The region of a continent that has been structurally stable for a prolonged period of time is called the craton.

A(n) _________ mountain range, such as the Basin and Range and Tetons, implies a horizontal extension strain.

The Appalachian Mountains are an example of ocean-ocean convergence.

Terranes that can be shown to have traveled great distances are known as _____ terranes.

Isostatic adjustment takes place during orogeny.

Geologists believe that when the thick and high part of a mountain belt becomes too high and gravitationally unstable _____ occurs.

In many mountainous regions are found ____, which are characterized by large thrust faults stacked one upon another.

In the Paleozoic Era the North American continent grew westward because of the accumulation of the Cordillera.

Fold and thrust belts are found in many mountain regions.

_____ are chains thousands of kilometers long composed of numerous mountain ranges.

Extension and normal faulting take place in a mountain range ____.