During an earthquake, if a footwall slides upward relative to a hanging wall (as shown in the figure below), the fault is termed a ________ fault.

In 1900, the most commonly used source of energy in the United States was ________; today it is ________.

Ash, cinders, and blocks are all types of ________.

A primary force opposing motion on all faults is ________.

Ash, cinders, and blocks are all types of ________.

Columnar joints form when ________.

A permeable and porous rock, regardless of lithology, is a good candidate to serve as a ________ in an oil-producing scenario.

Columnar joints form when ________.

The greatest depth at which oil is found is ________.

Most earthquakes are a result of ________.