GMAT - Reading Comprehension - Argument Evaluation - Deciphering relevant information
Prior to 1965 geologists assumed that the two giant rock plates meeting at the San Andreas Fault
Prior to 1965 geologists assumed that the two giant rock plates meeting at the San Andreas Fault generate heat through friction as they grind past each other, but in 1965 Henyey found that temperatures in drill holes near the fault were not as elevated as had been expected. Some geologists wondered whether the absence of friction-generated heat could be explained by the kinds of rock composing the fault. Geologists’ pre-1965 assumptions concerning heat generated in the fault were based on calculations about common varieties of rocks, such as limestone and granite; but “weaker” materials, such as clays, had already been identified in samples retrieved from the fault zone. Under normal conditions, rocks composed of clay produce far less friction than do other rock types.
In 1992 Byerlee tested whether these materials would produce friction 10 to 15 kilometers below the Earth’s surface. Byerlee found that when clay samples were subjected to the thousands of atmospheres of pressure they would encounter deep inside the Earth, they produced as much friction as was produced by other rock types. The harder rocks push against each other, the hotter they become; in other words, pressure itself, not only the rocks’ properties, affects frictional heating. Geologists, therefore, wondered whether the friction between the plates was being reduced by pockets of pressurized water within the fault that push the plates away from each other
Question 1. The passage suggests which of the following regarding Henyey’s findings about temperature in the San Andreas Fault?
A. Scientists have yet to formulate a definitive explanation for Henyey’s findings.
B. Recent research suggests that Henyey’s explanation for the findings should be modified.
C. Henyey’s findings had to be recalculated in light of Byerlee’s 1992 experiment.
D. Henyey’s findings provided support for an assumption long held by geologists.
E. Scientists have been unable to duplicate Henyey’s findings using more recent experimental methods.
Question 2. The passage is primarily concerned with?
A. evaluating a method used to test a particular scientific hypothesis
B. discussing explanations for an unexpected scientific finding
C. examining the assumptions underlying a particular experiment
D. questioning the validity of a scientific finding
E. presenting evidence to support a recent scientific hypothesis
A. This answer choice is right. We find the evidence for this in the last line of the passage; ''Geologists therefore wondered whether the friction between the plates was being reduced by pockets of pressurized water within the fault that push the plates away from each other''.
B. There is no evidence to suggest that Henyey's findings must be modified.
C. In Byerlee's 1992 experiment, different types of rocks were studied and not Henyey's findings.
D. This is the opposite of what actually happened, hence it's the wrong answer choice.
E. There is no evidence for this hence it can be eliminated.
A. The passage is not evaluating one method, in fact, it discusses different methods employed to study a particular phenomenon.
B. This is the correct answer choice as there are discussions taking place to understand the reason behind the heating of San Andreas Fault.
C. Though the passage talks about an experiment, it's not the primary idea of the passage.
D. The passage is not questioning the validity but is trying to find the reason behind the heating of San Andreas Fault.
E. The last line suggests that there is no concrete conclusion, hence this answer choice is incorrect.