The huge volume of mafic magma that erupted to form the Columbia plateau basalts of Washington and Oregon are attributed to ________.
A. sea floor spreading
B. subduction
C. a hot mantle plume
D. meteorite impact
E. magma mixing
Answer: C
You might also like to view...
An electron de-excites from the fourth quantum level to the third and then directly to the first. Two frequencies of light are emitted. How do their combined energies compare to the energy of the single frequency that would be emitted by de-excitation from the fourth level directly to the first level? The combined energies of the two frequencies emitted by the one electrons is
A. not predictable because other factors, such as the temperature of the surroundings must also be considered. B. equal to the energy of the single frequency. C. greater than the energy of the single frequency. D. less than the energy of the single frequency.
The United States already injects about 48 million tons of carbon dioxide underground each year. Indicate whether the statement is true or false
Pollutants vary in their persistence, which means some ____.?
A) ?reside in the environment for thousands of years, whereas others last for only a few minutes B) ?are toxic to organisms in tiny concentrations C) ?may seem harmless, but could be very deadly to distant species D) ?may interfere directly or indirectly to marine populations
An airplane flown by an untrained pilot is likely to crash if it flies through a downburst
Indicate whether the statement is true or false