Points Earned 001 Correct Answers D 5 Rocks in continents are on average much

Points earned 001 correct answers d 5 rocks in

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Points Earned:0.0/1.0Correct Answer(s):D 5.
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Rocks in continents are on average much older than sea-floor rocks. The likely explanation is: A) Techniques used to estimate the age of the rocks all yield perfect ages for continentalB) For a long time the Earth had continents but no sea floor; only recently, Death-Valley-C) For a long time the Earth had continents but no sea floor; only recently, continents D) Old sea floor is recycled back into the deep mantle at subduction zones at the same E) So much undersea mining has been conducted to get valuable metals from old sea-Feedback: Subduction balances sea-floor production very very closely, so the planet retainsthe same size and density distribution over time. Continents have grown slowly, but once made, the low-density continental rocks stay on the surface, whereas sea-floor rocks are lostto the deep mantle at subduction zones. Geological evidence indicates that we have had ocean basins since just after the formation of the planet. And undersea mining so far has been very tiny and localized.rocks but wild errors for sea-floor rocks, and sea-floor rocks are really as old as the continents.type spreading has split continents to make sea floor.sank and allowed lakes to grow into oceans.rate that new sea floor is produced, but continents are not taken into the mantle and so remain on the surface for a long time.floor rocks that all of the old ones have been ground up by people.Points Earned:0.0/1.0Correct Answer(s):D 6.You see a hot-spot volcano on the surface of the Earth. What is under this volcano? bottom of the mantle.
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E 7.Hot spots: altered in composition coming through a continent, in which case the volcano may be more andesitic.altered in composition coming through a continent, in which case the volcano may be more basaltic.
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