1.Which of the following is not expected very often near a “textbook” subduction zone (that is, neara subduction zone that is so perfect and free of confusing complications that you would use it in atextbook to teach students)?A) Piles of sediment scraped off the slab being subducted.B) Explosive volcanoes fed by melt from the slab being subducted.C) Stratovolcanoes formed by explosions and lava from the slab being subducted.D) Push-together earthquakes and faults as the subducting slab squeezes the rocks.E) Slide-past (or transform, with horizontal but no vertical movement) earthquakes and faultsFeedback: Most of the action at subduction zones is “push-together”, including push-together earthquakes and faults, scraping off of sediment to make piles as one side moves under the otherside, and volcanic explosions that contribute to layered volcanoes, or “stratovolcanoes”. Slide-past motion is not dominant, intermediates between pure subduction and pure slide-past motion do exist, but are not “textbook” cases of subduction.such as the San Andreas.Table for Individual Question FeedbackPoints Earned:1.0/1.0Correct Answer(s):E2.Much melting in the mantle occurs near subducting slabs primarily because:to be warmer than elsewhere in the mantle.
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- Fall '08
- Correct Answer, Volcano, Individual Question