Exam 6: The Active Earth: Plate Tectonics

Fossil distribution on continents had no bearing on Alfred Wegener's theory about continental drift.

The inner core is molten.

Alfred Wegener proposed in his __________ __________ theory that Earth's continents were once joined together and later split and moved apart.

According to the supercontinent model:

When a plate carrying continental crust converges with a plate carrying oceanic crust:

A mantle plume is a __________.

A plate is a segment of the lithosphere; thus, it includes the uppermost mantle and all of the overlying crust.

The lithosphere is:

Where two lithospheric plates of different densities converge, the denser one sinks into the mantle beneath the other in a process called __________.

Where two plates carrying ocean crust converge:

Where two plates move horizontally toward each other, they form a __________ boundary.

The outer 75 to 125 kilometers of the Earth, including both the crust and upper mantle, consists of:

The Himalayan Mountain Range is an example of a __________ boundary.

Average oceanic crust is __________ kilometers thick, whereas average continental crust is __________ kilometers thick.

The __________ is the Earth's thinnest layer.

A continent can be pulled apart at a divergent boundary in a process called __________ __________.

Where two plates carrying continental crust converge, they form:

The Mid-Oceanic Ridge is elevated above surrounding sea floor because it is made of hot and low-density lithosphere.

Alfred Wegener named his supercontinent __________.

The layer of the Earth that is as hot as the surface of the Sun is the inner __________.