hard · GRE Verbal

Passage: For decades the abundance of a certain deep-sea mineral nodule was taken as proof that the ocean floor was a stable, slowly changing environment; only in near-motionless conditions, it was reasoned, could nodules accrete over the millions of years their size implied. New seafloor imaging has inverted the argument. The nodules turn out to require periodic disturbance—faint bottom currents that lift them just enough to prevent burial by sediment. Left undisturbed, a nodule would be entombed and its growth arrested. Their very abundance, once cited as evidence of stillness, now testifies to intermittent motion. The revision is a reminder that a body of data can support opposite conclusions depending on the mechanism one assumes connects it to the world. The passage as a whole is primarily concerned with: (A) cataloguing the physical conditions under which deep-sea mineral nodules form (B) showing how the same evidence came to support a conclusion opposite to the one it once did (C) demonstrating that the ocean floor is far more turbulent than any prior model allowed (D) criticizing earlier oceanographers for reasoning carelessly from limited data (E) proposing a new method of seafloor imaging for detecting bottom currents

1. Cataloguing the various physical conditions under which deep-sea mineral nodules form
2. Showing how the same evidence came to support a conclusion opposite to the one it once did
3. Demonstrating that the deep ocean floor is far more turbulent than nearly any prior model allowed
4. Faulting earlier oceanographers for reasoning too carelessly from limited data
5. Proposing an entirely new method of seafloor imaging capable of detecting faint near-bottom currents

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