[求助]GWD-1-6

sandy07627

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.

Q6:

The passage mostly agree that Heney’s findings about temperature in the San Andreas Fault made the greatest contribution in that they     

 

1. revealed an error in previous measurements of temperature in the San Andreas Fault zone
2. indicated the types of clay present in the rocks that form the San Andreas Fault
3. established the superiority of a particular technique for evaluating data concerning friction in the San Andreas Fault
4. suggested that geologists had inaccurately assumed that giant rock plates that meet at the San Andreas Fault generate heat through friction
5. confirmed geologists’ assumptions about the amount of friction generated by common varieties of rocks, such as limestone and granite

answer is D.

我觉得文章最后不是说不光是石头的种类影响摩擦热，压力也是一个很重要的因素。

我觉得的答案应该是A，不是吗。因为文章对于摩擦产生热量没有表示异议，只是对measurements of temperature 不光是石头的种类还应该包括压力这一个因素。

谢谢哪位NN帮我看看吧。实在是想不通。

[此贴子已经被作者于2008-8-16 0:12:05编辑过]

dianecarton

The passage mostly agree that Heney’s findings about temperature in the San Andreas Fault
                made the greatest contribution in that they     

Do pay attention to the the key word--"greatest"

sandy07627

还是不十分的明白呢。因为我找不到任何地方说明giant rock plates that meet at the San Andreas Fault generate heat through friction 这个假设是错的。

又仔细看了一遍文章，是不是因为文章中一直没有合理的解释为什么温度比预计的要低（假设过可能是因为石头的种类不同，后来也给推翻了），所以就说一开始的geologists 估计的摩擦生热是不对的？

dianecarton

A.revealed an error in previous measurements of temperature in the San Andreas Fault zone.这里不存在错误的问题，定位原文but in 1965 Heney found that temperatures in drill holes near the fault were not as elevated as had been expected.是说Heney发现断层附近钻口的温度并没有预计的那么高。继续往下看，地质学家因此产生了一个疑问，既然这种温度低于rocks摩擦产生的温度，那么是否能够以rocks的构成来解释断层形成的原因呢？（提出新构想)。进一步分析得到1965年以前地质学家在预计岩石摩擦产生的温度时只考虑到limestone and granite等rocks，而忽略相对较软的clays等物质，而从fault提取出的样品中证明了clays的存在。然后第一段结尾提到由calys构成的rocks产生的摩擦相对较少。

以上对第一段的分析，我们可以知道，Heney的发现不是解释了一个温度测量上的错误，而是发现了一个与预计温度情况有差距的实际异常，而这一异常推到了地质学家关注岩石的成分，得到更准确的结论，就是由于岩石构成成分种有粘土等物质的存在，所以产生的摩擦并没有理论中那么大。然后第二段进一步分析了除了岩石的构成，压力也是影响摩擦热量的原因。

D.suggested that geologists had inaccurately
                assumed that giant rock plates that meet at the San Andreas Fault generate heat through friction

D选项是说地质学家对断层岩石块摩擦生热做了不准确的构想，是对的。注意D选项并没有否定摩擦生热本身，而是强调inaccurately
            assumed 。

sandy07627

原来是inaccurately这个词有推敲呢，inaccurately 不等于 incorrectly,  谢谢了，明白了。