Points Earned:1.0/1.0Correct Answer(s):B 3.Continents: A) Have grown in area over time primarily because convection cells stretched and B) Have not changed their areas over time.C) Have grown in area over time primarily by hot spots erupting through continents to D) Once covered the entire surface of the Earth, but have shrunk over time as E) Have grown in area over time primarily by addition of island arcs, seamounts and Feedback: Observations show that the continents have grown, as pieces were added to the continent sides; the centers of continents are very old, and then younger rocks occur in beltsaround the old cores. If you kept loading the conveyor-belt at the grocery store, but there were no baggers and you refused to bag your own, you’d end up with a giant clot of groceries mashed together at the end. That is not a bad model for how continents form. If a thinned continents but never pulled them apart to make new ocean basins.produce suspect terranes.convection cells pulled them apart to make ocean basins.sediments scraped off subducting slabs.
watermelon runs into a loaf of bread, you get a big mountain-building event! Hot spots poke through continents occasionally, but don’t cause much spreading so don’t cause much continental growth. “Suspect terrane” is an old geologic term for rocks that drifted in on a subducting slab and then mashed up onto a continent. Geologists long “suspect”ed that these “terranes” were weird, and eventually figured out the explanation, but named them before learning the explanation. Continents can be stretched and thinned at spreading centers, and some of those spreading centers do fail and leave a stretched continent that hasn’t broken to make an ocean, but more commonly the stretching continues until an ocean is made.Points Earned:0.0/1.0Correct Answer(s):E 4.The stiff basaltic rocks of the sea floor are bent as they enter subduction zones. This means that: form the deepest parts of the ocean.coast ranges of California.include the deepest water in the ocean.sediment washed from nearby land.produced a deep trench, which has been filled with discarded Microsoft Windows CDs, thrown away by people sick of all the viruses.
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