Author: Anonymous

Repeated eruptions of relatively fluid lava from fissures can eventually cause an area to be covered by flood basalts.

The large mineral grains in a porphyritic igneous rock are called ________.

The crust, mantle, and outer core are solid.

Aa flows are generally thinner and have smoother surfaces than pahoehoe flows.

The Columbia Plateau in Washington and Oregon is ________.

Peat is thought to be the original material from which coals are formed.

The distance between a seismological recording station and the earthquake source is determined from the ________.

Which of the following shoreline features forms only in tectonically active areas?

Aa flows are generally thinner and have smoother surfaces than pahoehoe flows.

Which was the most powerful, explosive volcanic eruption of historic time?