[ Update : This question has been nominated for Bounty. The user who gives the best answer/explaination will receive a free GMAT book]
Prior to 1965 geologists assumed that the two giant rock plates meeting at
the San Andreas Fault generate heat Line 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 won-
dered 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
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.
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