Exam 3: Plate Tectonics

It is not possible to estimate rates of plate movement because new rocks are constantly being created from old.

Sea floor is formed at spreading ridges and destroyed

These are areas not connected with plate boundaries but are regions of volcanic activities and are use to monitor the direction and movement of plates are called

Earthquakes occur at subduction zones,but volcanoes do not because the subducted lithosphere is pushed deep into the mantle.

Stress tending to pull objects apart is __________ stress.

Brittle behavior in rocks leads to formation of folds.

Plate tectonics are unrelated to the rock cycle and,in fact,has made the rock-cycle concept obsolete.

Deep in the crust,at elevated temperatures,rocks may behave plastically and undergo folding or flow.

The physical properties of a rock are determined only by grain shapes and sizes and are independent of the kinds of minerals making up the rock.

Plate boundaries were originally located by a French graduate student who plotted the location of all earthquakes and volcanic eruptions world-wide on a map.

Part of western California is attached to the Pacific Plate,while most of North America belongs to a separate plate.

The locations and ages of islands in the Hawaiian Island chain can be used to show