Exam 4: Plate Tectonics

The portion of a fracture zone between two offset portions of ridge crest is called a ____.

Hess's original hypothesis was that sea-floor spreading is driven by deep mantle ____.

The Peru-Chile trench is moving over the ________ Plate as South America moves west.

All transform faults connect two ridge segments.

The head of large plumes that form "hot spots" may cause uplift and ____.

One possible mechanism for plate tectonic drive is ____.

____ volcanoes can be found along subducting plate boundaries.

An island arc is a string of volcanoes parallel to the oceanic trench

Pangea initially separated into two parts,a northern supercontinent,and a southern supercontinent.

When a ridge subsides sea level may rise.

Suture zones in continents mark old sites of mantle plumes.

As a descending plate reaches depths of about 100 km,magma is generated in the overlying asthenosphere.

_______ proposed an explanation for magnetic anomalies.

Wegener reassembled the continents to form the super continent _____.

One kind of convergent plate boundary is ____.

Recent studies using seismic tomography indicate that whole mantle convection is the best model.

A divergent boundary on the sea floor is associated with ______.

Wegener reassembled the modern continents to form the giant super continent of Gondwanaland.

The Himalayan Mountains are thought to have formed ____.

In the early 1900s the German meteorologist _____ made a strong case for continental drift.