NAEP Science Grade 12

Category - Earth Science

In New England, it is common to find striations in the surface of exposed rock outcrops. These linear grooves are primarily produced by:
  1. Ice that is well below its freezing point at the base of surging glaciers.
  2. Extreme temperature changes that produce fractures in the bedrock underlying glaciers.
  3. Large rocks that are embedded in the base of glaciers.
  4. Silt-rich water under tremendous pressure at the base of continental glaciers.
Explanation
Correct Response: C. Striations in the bedrock of glaciated regions are linear gouges and scratches in bedrock produced by rocks stuck to the bottom of a cold-based glacier. Glacial ice is capable of eroding rock, but is not strong enough to create long linear gouges (A) in bedrock. Extreme temperature changes can cause mechanical weathering, but do not produce the long linear scratches and gouges that comprise striations (B). Although sub-glacial, sediment-rich water can erode the bedrock beneath a glacier, it does so relatively evenly and does not produce striations (D).
Was this helpful? Upvote!
Login to contribute your own answer or details

Top questions

Related questions

Most popular on PracticeQuiz