The Appalachian Mountains May Have Once Been as Lofty as the Himalayan-

question 46

Multiple Choice

The Appalachian Mountains may have once been as lofty as the Himalayan- Tibetan Mountain belt is today. Why are they not this high now?

• A) They developed a dense crustal root following collision, and isostasy forced them to sink to their present elevation.
• B) They formed long ago, and erosion has beveled them to their present low elevation.
• C) Opening of the North Atlantic Ocean converted lithosphere to asthenosphere beneath eastern North America, forcing eastern North America to sink to low elevations.
• D) The mountains cooled following the collision, which increased the density of the of the rocks by cooling, and isostasy forced the mountains to sink.

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Definitions:

Terminal Illness

A disease or condition that is incurable and expected to lead to the death of the patient within a relatively short period of time.

General Adaptation Syndrome

A three-stage response (alarm, resistance, exhaustion) that the body goes through when exposed to prolonged stress, as proposed by Hans Selye.

Panicked

A sudden, overwhelming feeling of fear or anxiety that often results in hasty or irrational behavior.

Alarm Reaction

A phase in the general adaptation syndrome where the body initially responds to a stressor with changes that temporarily lower resistance.