Duplicate of Plate Tectonics

About ______ years ago, the continents were joined together in one supercontinent.

The longest mountain ranges in the world are found in ......

It takes 100,000 years for a plate to move 2 Km. What is the rate in centimeters per year?

In the mid-1900's scientists mapped the ocean floor using......

In a process taking tens of millions of years, part of the ocean floor sinks back into the __-.

The San Andreas Fault is an example of which type of plate boundary?

the most outer layer of the Earth.

Earth's plates move apart at ______ boundaries.

Which of the following is not evidence of sea-floor spreading?

A large landmass is called .....

Changes in the Earth's magnetic field creates magnetic ____ on the ocean floor.

Alfred Wegener called the supercontinent.....

Earth's plates slip past each other at ______ boundaries.

Where pieces of Earth's crust diverge on land, a deep valley called a _____ valley forms.

The process of  _____ allows ocean floor to sink back into the mantle.

Which of the following is not produced by a convergent plate boundary?

What has happened to the Earth's magnetic field over millions of years?

The theory of _____ ______  states that the Earth's plates are in slow constant motion.

Near which letter would you find magnetic stripes?

Which letter would represent a deep ocean trench?

In 1910, this scientist theorized that the continents had moved.

This process adds more crust to the ocean floor.

A chain of mountains that runs along the middle of the ocean floor.

Earth's plates move together at _____ boundaries.

Wegener thought that the coastlines of Africa and  _______ seemed to match up.

Deep scratches caused by _____ have been found in rocks of South Africa. 

Select the densest type of Earth's Crust.

The theory that the continents are moving is called.....

_________ currents in the Earth's mantle cause plates to move along _____ .

Most geologists originally ______ Wegeners idea of continental drift.