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
(5) 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
(10) friction-generated heat could be
explained by the kinds of rock com-
posing the fault. Geologists' pre-1965
assumptions concerning heat gen-
erated in the fault were based on
(15) 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
(20) 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
(25) 10 to 15 kilometers below the Earth's
surface. Byerlee found that when clay
samples were subjected to the thou-
sands of atmospheres of pressure
they would encounter deep inside the
(30) 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
(35) 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.
By reading first 3 three lines of each paragraph, every answer looks wrong for me. After reading the last lines in the 2 paragraph I could find the answer.
first they thought that rock composition is the reason for difference in heat. After the experiment with clay, scientist thought that rock composition has no role in generating heat. this implies that the issue of heat difference is not solved.
2.The passage is primarily concerned with
A.evaluating a method used to test a particular scientific hypothesis. (We are not finding whether the argument is right. We are trying to find the reason for heat differences)
B.discussing explanations for an unexpected scientific finding
(Unexpected scientific finding:Heat Difference, which is not usual. First, rock composition might be the reason. Then, Rock composition has no role.)
C.examining the assumptions underlying a particular experiment (NO
D.questioning the validity of a scientific finding (We are finding the reasons for scientific findings not the questioning the findings)
E.presenting evidence to support a recent scientific hypothesis
