Exam 2: Plate Tectonics: The Unifying Theory

Roughly when did most earth scientists accept plate tectonics as a theory?

What type of plate boundary is parallel to the direction of plate movement?

When was the theory of plate tectonics developed?

The Earth's lithosphere is broken up into approximately _____ large plates.

Oceanic crust that records negative magnetic anomalies formed when the Earth's magnetic field was

Compared with oceanic crust the continental crust is generally lighter,____ and _____.

Who proposed the theory of continental drift?

Compared with oceanic rifts the continental rifts generally lack

When did India begin to collide with Asia to form the Himalayas?

Mid-ocean ridges are also referred to as

How many major plates cover Earth's surface?

What drives plate tectonics?

Astronomical positioning measures points on the Earth's surface relative to

Roughly how long has the North American Plate been around?

Pangaea split into two continents: Laurasia,made up of the northern continents,and ______,made up of the southern continents.

When did the supercontinent Pangaea begin to break apart?

How do we determine absolute direction of plate movement over millions of years?

The main type of plate boundaries are (proper names only):

When a deep-sea trench is located next to a continent,where would you expect to find active volcanoes?

Compared with slower moving plates,faster moving plates are bounded by a greater proportion of