問題詳情
Questions 1-9With the onset of the Industrial Revolution, knowing the age of rocks became anecessary prerequisite to finding industrial minerals, such as coal, iron, and theother materials that fueled and sustained the great Western industrialization of the eighteenthLine and nineteenth centuries. It was in the mining regions where engineers, who needed a5 better system for organizing the various types of rock scattered across Earth's surface,first grappled with scientific approaches to understanding the age of various rocks—andthe age of Earth. They realized that if the various rock units could he dated by theirrelative ages, correlations among even widely separated rocks could be established andfrom this, some order recognized.10 The pioneering European geologists first believed that identifying a rock's type wouldgive them a strong clue to the age of the rock formation and that one of the most powerfulclues came from the hardness of a given rock. Specific rock types were thus assumed tohave formed at characteristically different rimes, the softest rocks having formed the mostrecently. This crude type of dating was first used to understand the way mountains were15 formed, In the mid-1700's it was thought thai there were three distinct types of mountainsin Europe, each formed by a different type of rock and each created at a different time.According to this theory, the oldest were the Alps, which had interior cores composedof very hard, crystalline rocks (such as granite, schist, or basalt). These mountains werecalled Primitive. Sitting on the flanks of the Primitive mountains were younger, smaller,20 Secondary mountains composed of layered sedimentary rocks such as limestone.They were often rich with fossils and intermediate in hardness. The youngest Tertiarymountains were composed of softer mudstones and sandstone. Rock type, hardness,and size thus established mountain type, and rock type also became a proxy for age.However, study soon exposed the fallacy of these early notions. It was discovered that25 some of the very high mountains were composed of the softest sediments and that evenhard volcanic rock was sometimes found in very low mountains. By the early 1800's, itwas understood that rock type was of no help in establishing age.
【題組】1, What does the passage mainly discuss?
(A) An early attempt to find reliable rules for dating rocks and mountains
(B) The search for different rock types to be used in industry
(C) Changing views about what caused high mountain ranges to form
(D) A controversy about rocks between mining engineers and geologists
參考答案
答案：A
難度：適中0.50885
統計：A(115),B(68),C(19),D(20),E(0)