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- Sat Jun 03, 2017 1:47 pm
#35686
Complete Question Explanation
(See the complete passage discussion here: lsat/viewtopic.php?t=14347)
The correct answer choice is (B)
To support the ocean floor spreading theory, consider the evidence presented in the third paragraph
and identify an answer choice that makes a similar point. As with many scientific arguments, this
one is based on causal reasoning whereby empirically observed evidence (the effect) is explained by
a reference to a particular hypothesis (the cause). The techniques used to strengthen causation in the
Logical Reasoning section of the test should prove equally helpful in attacking this question as well.
Answer choice (A): Since basalt makes up much of the ocean floor, the fact that other types of rock
share the same odd magnetic variations as basalt is irrelevant. This proposition does not lend any
additional support to the ocean floor spreading theory.
Answer choice (B): This is the correct answer choice. If the ages of the earth’s magnetic reversals
have been verified by means other than examining magnetite grains in rock, this would make it even
easier to compare the known ages of magnetic field reversals with the striping pattern of the ocean
floor. Such data would lend additional support to the correlation described in the third paragraph, and
in turn strengthen the ocean floor spreading theory.
Answer choice (C): Just because the continental basalt is similar to the type found on the mid-ocean
ridge does not support the ocean floor spreading theory. For this answer to be attractive, we would
need to establish that the continental basalt exhibits a magnetic striping pattern suggestive of a
process similar to the ocean floor spreading, which is not presented or alluded to in the passage.
Answer choice (D): This answer choice may seem attractive, as the variation in peak height along
the ridge could be interpreted as evidence that some ridges are more structurally weak than others,
allowing more magma to escape through them. Even so, it is entirely possible that a different
geological or oceanic process was responsible for this variation. Furthermore, the author never
alludes to the fact that some ridges mark zones that are structurally weaker than others, adding
another reason why answer choice (D) is incorrect.
Answer choice (E): Even if basalt were the only type of submarine rock found near the continents,
this would neither support nor weaken the ocean floor spreading theory.
(See the complete passage discussion here: lsat/viewtopic.php?t=14347)
The correct answer choice is (B)
To support the ocean floor spreading theory, consider the evidence presented in the third paragraph
and identify an answer choice that makes a similar point. As with many scientific arguments, this
one is based on causal reasoning whereby empirically observed evidence (the effect) is explained by
a reference to a particular hypothesis (the cause). The techniques used to strengthen causation in the
Logical Reasoning section of the test should prove equally helpful in attacking this question as well.
Answer choice (A): Since basalt makes up much of the ocean floor, the fact that other types of rock
share the same odd magnetic variations as basalt is irrelevant. This proposition does not lend any
additional support to the ocean floor spreading theory.
Answer choice (B): This is the correct answer choice. If the ages of the earth’s magnetic reversals
have been verified by means other than examining magnetite grains in rock, this would make it even
easier to compare the known ages of magnetic field reversals with the striping pattern of the ocean
floor. Such data would lend additional support to the correlation described in the third paragraph, and
in turn strengthen the ocean floor spreading theory.
Answer choice (C): Just because the continental basalt is similar to the type found on the mid-ocean
ridge does not support the ocean floor spreading theory. For this answer to be attractive, we would
need to establish that the continental basalt exhibits a magnetic striping pattern suggestive of a
process similar to the ocean floor spreading, which is not presented or alluded to in the passage.
Answer choice (D): This answer choice may seem attractive, as the variation in peak height along
the ridge could be interpreted as evidence that some ridges are more structurally weak than others,
allowing more magma to escape through them. Even so, it is entirely possible that a different
geological or oceanic process was responsible for this variation. Furthermore, the author never
alludes to the fact that some ridges mark zones that are structurally weaker than others, adding
another reason why answer choice (D) is incorrect.
Answer choice (E): Even if basalt were the only type of submarine rock found near the continents,
this would neither support nor weaken the ocean floor spreading theory.