Quiz 3

If two oceanic plates collide at a relatively fast speed, and one is much older and cooler (therefore denser) than the other, what will probably happen?

A trench will form. Continental mountains will form. Large earthquakes will occur. **All of the above**

As you know, Earth is layered inside. The layers have different thicknesses and densities. How do geologists knows this?

From observing the transit times through the Earth of waves generated by large earthquakes.

The force driving the lithospheric plates is believed to be:

Gravity.

New crust is being generated:

In the rift valleys of the mid-ocean ridges.

When a substance is resting in buoyant equilibrium, moving neither up nor down:

It displaces a volume of water equal in weight to its own weight.

What is the name of the outermost solid layer of the Earth?

lithosphere.

Which of these is the most abundant on or in the Earth?

mantle material.

Here are five lists of elements. Which list represents the main components of the Earth's crust?

oxygen, silicon, aluminum.

Land-based evidence for plate tectonics can be seen in:

the distribution of Glossopteris flora and fauna. evidence of ancient glaciation. the lineation of mountain ranges. the correlation of rocks in now widely separated continents. **all of these**

The mid-ocean ridges are recognized as:

divergent plate boundaries