Exam 3: Earth Structure and Plate Tectonics

Scientists believe the breakup of Pangaea occurred about ____.

One piece of evidence that suggests the existence of Pangaea is the discovery of Mesosaurus fossils in Argentina and Africa, but nowhere else.

One cubic meter of which of these would weigh the most?

About how many kilometers (miles)is it from the center of Earth to the outer edge of the outer core?

A "mystery" in our understanding of plate tectonics has been, until recently, the nature of the power source capable of moving the plates and the continents embedded within them. Recent evidence indicates the power source to be ____.

Some plateaus, ocean ridges, ancient island arcs, and parts of continental crust are too buoyant to be subducted. These are, instead, squeezed and sheared onto the face of a continent, forming ____.

As early as the 1700s, scientists and observers noticed a remarkable coincidence of shape of the Atlantic coasts of Africa and ____.

New crust is being generated ____.

The Himalayan Mountains were formed as a result of ____.

There are two types of plate divergences: divergent oceanic crust and divergent continental crust.

The rigid outer layer of Earth that comprises both continental and oceanic crust is called the ____.

What kind of observational evidence did Alfred Wegener use to propose his theory of continental drift, and the idea that the continents were once connected as the single landmass, Pangaea?

If two oceanic plates collide and one is older and cooler (therefore more dense)than the other, what will happen?

How has the history of plate movement been captured in residual magnetic fields?

The hot, partially melted, slowly flowing layer of Earth is called the ____.

The mid-ocean ridges are ____.

Earlier than 200 million years ago, the continents were joined into one supercontinent called ____.

The youngest seafloor rocks are found ____.

Roughly how fast do most lithospheric plates move?

California's San Andreas fault is which type of plate boundary?