During the seventeenth and eighteenth centuries, before geology became the scientific discipline it is today, people believed that all Earth’s features had been produced by a few great catastrophes. Those catastrophes were thought to be so huge that they could not be explained by ordinary processes but must have supernatural causes. This concept came to be called catastrophism. The catastrophes were thought to be gigantic and sudden, and they were also thought to have occurred relatively recently.
During the late eighteenth century the concept of catastrophism was reexamined, compared with geologic evidence, and found wanting. The person who assembled much of the evidence and proposed a counter theory was James Hutton. a Scottish physician and gentleman farmer. who was intrigued by what he saw in the environment around him. He observed the slow but steady effects of erosion: the transport of rock particles by running water and their ultimate deposition in the sea. He reasoned that mountains must slowly but surely be eroded away. that rocks must form from the debris of erosion, and that those rocks in turn must be slowly thrust up to form mountains. Hutton didn’t know the source of the energy that caused mountains to be thrust up, but he argued that everything moved slowly along in a continuous, repetitive cycle.
Hutton’s ideas evolved into what we now call the principle of uniformitarianism, which states that the same external and internal processes that we recognize in action today have been operating throughout Earth’s history. We can examine any rock, however old and compare its characteristics with those of similar rocks that are forming today in a particular environment. We can then infer that the ancient rock very likely formed in the same sort of environment. For example, in many deserts today we can see gigantic sand dunes formed from sand grains transported by the wind. Because of the way they form, the dunes have a distinctive internal structure. Using the principle of uniformitarianism, we can safely infer that any rock composed of cemented grains of sand and having the same distinctive internal structure as modern dunes is the remains of an ancient dune.
Geologists since Hutton’s time have explained Earth’s features in a logical manner by using the principle of uniformitarianism. But in so doing they have made an outstanding discovery—Earth is incredibly old. An enormously long time is needed to erode a mountain range, or for huge quantities of sand and mud to be transported by streams, deposited in the ocean, and cemented into new rocks, and for the new rocks to be deformed and uplifted to form a new mountain. Yet, slow though it is, the cycle of erosion formation of new rock, uplift, and more erosion has been repeated many times during Earth’s long history.
During the nineteenth century, geologists tried to estimate the duration of the rock cycle by estimating the thickness of all the sediments that have been laid down through geologic time. They assumed that the principle of uniformitarianism applied to the rate sat which processes occur as well as to the processes themselves and hence that rates of deposition of sediment have always been constant and equal to today’s rates. Thus, they thought, it would be a simple calculation to estimate the time needed to produce all the sediments. The results, we now know, were greatly in error. One of the reasons for the error was the assumption of constancy of geologic rates.
The more we learn about Earth’s history and the more accurately we determine the timing of past events through radiometric dating (using rates of decay of naturally occurring radioactive atoms to determine the ages of rocks), the clearer it becomes that rock cycle rates have not always been the same. Some rates were once more rapid, others much slower. This means that the relative importance of different geologic processes has probably differed in the past. For example, just because glaciation is an important process today, we cannot assume that it has been equally important throughout geologic time. But we can assume that when glaciation did affect Earth in geologically remote times the processes and effects were the same as those we observe in glaciated regions today.
题目：
1
During the seventeenth and eighteenth centuries, before geology became the scientific discipline it is today, people believed that all Earth’s features had been produced by a few great catastrophes. Those catastrophes were thought to be so huge that they could not be explained by ordinary processes but must have supernatural causes. This concept came to be called catastrophism. The catastrophes were thought to be gigantic and sudden, and they were also thought to have occurred relatively recently.
According to paragraph 1, what is catastrophism?
AThe explanation of Earth’s geologic features as the result of a few enormous geologic events of supernatural origin
BThe attempt to explain sudden, violent catastrophes as the result of ordinary geologic processes
CThe first truly scientific explanation of the formation of Earth’s geologic features
DThe view that geologic processes gradually unfold over time but nevertheless tend to be catastrophic in their results
2
During the seventeenth and eighteenth centuries, before geology became the scientific discipline it is today, people believed that all Earth’s features had been produced by a few great catastrophes. Those catastrophes were thought to be so huge that they could not be explained by ordinary processes but must have supernatural causes. This concept came to be called catastrophism. The catastrophes were thought to be gigantic and sudden, and they were also thought to have occurred relatively recently.
During the late eighteenth century the concept of catastrophism was reexamined, compared with geologic evidence, and found wanting. The person who assembled much of the evidence and proposed a counter theory was James Hutton. a Scottish physician and gentleman farmer. who was intrigued by what he saw in the environment around him. He observed the slow but steady effects of erosion: the transport of rock particles by running water and their ultimate deposition in the sea. He reasoned that mountains must slowly but surely be eroded away. that rocks must form from the debris of erosion, and that those rocks in turn must be slowly thrust up to form mountains. Hutton didn’t know the source of the energy that caused mountains to be thrust up, but he argued that everything moved slowly along in a continuous, repetitive cycle.
It can be inferred from paragraphs 1 and 2 that the scientific study of geology began
Awith the discovery of the source of the energy that caused mountains to be thrust up
Bwhen James Hutton challenged the theory of catastrophism
Cwith an attempt to explain the great catastrophes that had occurred in the relatively recent past
Dwith an attempt to explain how rock particles deposited in the sea turn into rock
3
During the late eighteenth century the concept of catastrophism was reexamined, compared with geologic evidence, and found wanting. The person who assembled much of the evidence and proposed a counter theory was James Hutton. a Scottish physician and gentleman farmer. who was intrigued by what he saw in the environment around him. He observed the slow but steady effects of erosion: the transport of rock particles by running water and their ultimate deposition in the sea. He reasoned that mountains must slowly but surely be eroded away. that rocks must form from the debris of erosion, and that those rocks in turn must be slowly thrust up to form mountains. Hutton didn’t know the source of the energy that caused mountains to be thrust up, but he argued that everything moved slowly along in a continuous, repetitive cycle.
According to paragraph 2, what is the continuous cycle for which Hutton argued?
ARock is eroded; the eroded rock particles are transported by running water; the rock particles are deposited in the sea.
BRock is formed in the sea: those rocks are pushed up to form mountains; those mountains gradually sink into the sea
CEnergy is created by running water that energy causes mountains to be thrust up; those mountains are eroded by running water.
DMountains are eroded into debris; rocks are formed from the debris; those rocks are pushed up to form mountains.
4
Hutton’s ideas evolved into what we now call the principle of uniformitarianism, which states that the same external and internal processes that we recognize in action today have been operating throughout Earth’s history. We can examine any rock, however old and compare its characteristics with those of similar rocks that are forming today in a particular environment. We can then infer that the ancient rock very likely formed in the same sort of environment. For example, in many deserts today we can see gigantic sand dunes formed from sand grains transported by the wind. Because of the way they form, the dunes have a distinctive internal structure. Using the principle of uniformitarianism, we can safely infer that any rock composed of cemented grains of sand and having the same distinctive internal structure as modern dunes is the remains of an ancient dune.
In paragraph 3, why does the author discuss sand dunes?
ATo give an example of the geologic importance of desert environments
BTo show that wind transports rock particles as well as water
CTo illustrate how the principle of uniformitarianism is applied
DTo explain how certain types of rack are formed by specific environmental conditions
5
Hutton’s ideas evolved into what we now call the principle of uniformitarianism, which states that the same external and internal processes that we recognize in action today have been operating throughout Earth’s history. We can examine any rock, however old and compare its characteristics with those of similar rocks that are forming today in a particular environment. We can then infer that the ancient rock very likely formed in the same sort of environment. For example, in many deserts today we can see gigantic sand dunes formed from sand grains transported by the wind. Because of the way they form, the dunes have a distinctive internal structure. Using the principle of uniformitarianism, we can safely infer that any rock composed of cemented grains of sand and having the same distinctive internal structure as modern dunes is the remains of an ancient dune.
The word “distinctive” in the passage is closest in meaning to
Avisible
Bcharacteristic
Cstable
Dcomplex
6
During the nineteenth century, geologists tried to estimate the duration of the rock cycle by estimating the thickness of all the sediments that have been laid down through geologic time. They assumed that the principle of uniformitarianism applied to the rate sat which processes occur as well as to the processes themselves and hence that rates of deposition of sediment have always been constant and equal to today’s rates. Thus, they thought, it would be a simple calculation to estimate the time needed to produce all the sediments. The results, we now know, were greatly in error. One of the reasons for the error was the assumption of constancy of geologic rates.
According to paragraph 5, what led nineteenth-century geologists to an incorrect estimate of how long it took to produce all the sediments that have been laid down through geologic time?
ATheir belief that geologic processes have always occurred at the same rate as they do today
BTheir miscalculation of the rate at which sediments are being laid down today
CTheir failure to realize that the earliest sediments would have been completely covered over by later sediments
DTheir belief that the same geologic processes have been operating throughout Earth’s history
7
The more we learn about Earth’s history and the more accurately we determine the timing of past events through radiometric dating (using rates of decay of naturally occurring radioactive atoms to determine the ages of rocks), the clearer it becomes that rock cycle rates have not always been the same. Some rates were once more rapid, others much slower. This means that the relative importance of different geologic processes has probably differed in the past. For example, just because glaciation is an important process today, we cannot assume that it has been equally important throughout geologic time. But we can assume that when glaciation did affect Earth in geologically remote times the processes and effects were the same as those we observe in glaciated regions today.
According to paragraph 6, information from radiometric dating supports which of the following statements?
AMost geologic processes probably took longer during earlier periods of Earth’s history than they do today.
BGeologic processes that are relatively unimportant today might have been far more important in earlier periods of Earth’s history.
CSome geologic processes that are extremely important today probably did not occur during any earlier periods of Earth’s history.
DGeologic processes that have well-known effects today might have had very different effects during other periods of Earth’s history.
8
Geologists since Hutton’s time have explained Earth’s features in a logical manner by using the principle of uniformitarianism. But in so doing they have made an outstanding discovery—Earth is incredibly old. An enormously long time is needed to erode a mountain range, or for huge quantities of sand and mud to be transported by streams, deposited in the ocean, and cemented into new rocks, and for the new rocks to be deformed and uplifted to form a new mountain. Yet, slow though it is, the cycle of erosion formation of new rock, uplift, and more erosion has been repeated many times during Earth’s long history.
Paragraph 4 supports which of the following statements about Earth’s geological features?
AThey are largely unchanged since the time of Earth’s formation.
BThey form relatively rapidly on a scale of geologic time.
CThey are created through a cycle of processes that has occurred again and again over time
DThey mainly result from changes in the oceans that affect the formation of rocks.
