
Geosynclines, Mountains and Continent-Building
A geosyncline is a huge deposit of sedimentary rock that forms at the edge of a continent. When it is compressed, it buckles up into a mountain range. It also enables a continent to grow by accretion

Geosynclines, Mountains and Continent-Building
A geosyncline is a huge deposit of sedimentary rock that forms at the edge of a continent. When it is compressed, it buckles up into a mountain range. It also enables a continent to grow by accretion

The Breakup of Pangaea
Pangaea is the single land mass that is believed to have given rise to the present continents. Its outline has now been plotted and its further disruption has been projected into the future

The Sea's Deep Scattering Layers
The sound pulses of devices used to measure the depth of the ocean are often scattered by several "phantom bottoms" that rise by night and sink by day. The animals that make up these layers are now being identified

The Bathyscaph
In this remarkable vessel men can visit the ocean bottom at depths of more than 15,000 feet. Explorations with it are now yielding significant geophysical and biological information

The Pacific Floor
Modern methods of undersea exploration have pieced together a dramatic picture of this rugged landscape. A description of it in terms of an imaginary voyage in a supersubmarine