首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Early Theories of Continental Drift P1: The idea that the geography of Earth was different in the past than it is today is not n
Early Theories of Continental Drift P1: The idea that the geography of Earth was different in the past than it is today is not n
admin
2018-10-18
70
问题
Early Theories of Continental Drift
P1: The idea that the geography of Earth was different in the past than it is today is not new. As far back as 1620, Francis Bacon spotted that the west coast of Africa and the east coast of South America looked as if they would fit together, like pieces of a jigsaw puzzle. Between then and 1912, other people identified further similarities between other continental coastlines. But because much of the early support for mobilism was based on far-flung intercontinental similarities, geologists tended to be skeptical of the fieldwork of others.
P2: During the late nineteenth century, Austrian geologist Eduard Suess proposed the name "Gondwanaland" in his book The Face of the Earth (1885) and gave far greater emphasis to the evolutionary nature of the earth and he noted the similarities among the Late Paleozoic plant fossils of India, Australia, South Africa, and South America. Based upon glossopteris fern fossils in such regions, he explained that the three land masses were once connected in a supercontinent which he names Gondwanaland, and that the ocean flooded the spaces currently between those lands. Thus, in his view, the similarities of fossils on these continents could be accounted for by postulating the concept of a land bridge that existed once but subsided later.
P3: Later, a number of refinements to Suess’s theory were made. The American geologist Frank Taylor published a pamphlet in 1910 presenting his concept of "horizontal displacement". He explained the formation of mountain ranges as a result of the lateral movements of continents. With the earth’s capture of the moon, the gravitational forces between them generated a pull towards lower latitudes where they thickened and formed folded mountain belts especially in middle latitudes. Although we now know that Taylor’s explanation of continental drift is erroneous, one of his most significant contributions was his suggestion that the Mid-Atlantic Ridge— an underwater mountain range discovered by the 1872-1876 British HMS Challenger expeditions—might mark the site at which an ancient continent broke apart, forming the present-day Atlantic Ocean.
P4: However, it is Alfred Wegener, a German meteorologist, who is generally credited with developing the hypothesis of continental drift. In his monumental book, The Origin of Continents and Oceans (1915), Wegener theorized that a single supercontinent he called "Pangaea" existed sometime between 350 million to 225 million years ago. Wegner portrayed his grand concept of continental movement in a series of maps showing the breakup of Pangaea and the movement of various continents to their present-day locations. What evidence did Wegener use to support his hypothesis of continental drift? First, Wegener noted that there is geographical similarity along both the coasts of the Atlantic Ocean. The opposing coasts of the Atlantic can be fitted together in the same way as two cut off pieces of wood can be refitted. Furthermore, mountain ranges and glacial deposits seem to match up in such a way that suggests continents could have once been a single landmass. Finally, many of the same fossils and vegetative remains are found today on widely separated continents, indicating that the continents must have been in proximity at one time. During his days, Wegener was regarded as an advocate rather than as an impartial scientific observer, appearing to ignore vast evidence unfavorable to his ideas and distort other evidence to bring it into harmony with the theory.
P5: After Wegener’s death, a South African geologist Alexander Du Toit continued to assemble fossil evidence for Pangaea. He noted that fossils of the now extinct reptile "Mesosaurus" occur in rocks of the same age in both Brazil and South Africa. Because the physiology of freshwater and marine animals is completely different, it is hard to imagine how a freshwater reptile could have swum across the Atlantic Ocean and then found a freshwater environment nearly identical to its former habitat. Moreover, if Mesosaurus could have swum across the ocean, its fossil remains should be widely dispersed. It is more logical to assume that Mesosaurus lived in lakes in what were once adjacent areas of South America and Africa when it was united into a single continent. Notwithstanding all of the empirical evidence in favor of continental drift theory presented here, most geologists at the time refused to entertain the idea.
P6 :The debate over continental drift has the same role and stature in the history of the earth sciences as the debate over Darwinian evolution in the history of life sciences and the debates over relativity and quantum theory in the history of physics. In the largest sense, the history of earth science, the history of biology, and the history of physics in the 20th century are all histories of the consolidation of opinion and the formation of broad consensus—that these theories were the best way to organize and advance these sciences.
P5: After Wegener’s death, a South African geologist Alexander Du Toit continued to assemble fossil evidence for Pangaea.■ He noted that fossils of the now extinct reptile "Mesosaurus" occur in rocks of the same age in both Brazil and South Africa.■ Because the physiology of freshwater and marine animals is completely different, it is hard to imagine how a freshwater reptile could have swum across the Atlantic Ocean and then found a freshwater environment nearly identical to its former habitat. ■ Moreover, if Mesosaurus could have swum across the ocean, its fossil remains should be widely dispersed. It is more logical to assume that Mesosaurus lived in lakes in what were once adjacent areas of South America and Africa when it was united into a single continent. ■ Notwithstanding all of the empirical evidence in favor of continental drift theory presented here, most geologists at the time refused to entertain the idea.
According to paragraph 4, Wegener felt confident that his theory are correct in part because
选项
A、contemporary scientists were unable to successfully challenge his evidence.
B、many different types of evidence seemed to support his theory.
C、his theory accounted for phenomena that earlier theories could not explain.
D、he had used the most advanced techniques available to gather his evidence.
答案
B
解析
【事实信息题】题目问Wegener认为自己的理论正确是因为什么。文中提到“What evidence did Wegener use to support his hypothesis of continental drift?”并提出了三个理由,因此答案为B。
转载请注明原文地址:https://kaotiyun.com/show/X5fO777K
0
托福(TOEFL)
相关试题推荐
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.ROBERTSCOMPANYFoundingThemostimportantprincipa
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.ROBERTSCOMPANYFoundingThemostimportantprincipa
ChooseTWOletters,A-E.WhichTWOthingsmakethemuseumunusual?AtheguidesBtheeventsCtheanimalsDthebuildingsEthe
Whatdidthewomanfinddifficultaboutthedifferentresearchtechniquessheused?ChooseFIVEanswersfromtheboxandwritet
BeforeyoulistenLookatthetaskbelow.Trytoworkoutthesituationfromthetask.Whataretheytalkingabout?Whyarethey
WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.MonarchButterfliesHibernationButterflyspeciesadoptdifferent
LaughterThenatureoflaughterlaughterisa【L31】________process—involvesmovementandsounditiscontrolledbyour【
Basalt,(which)composes(most)oftheocean(floor),isadark-greyrock(rich)inironandmagnesiumthanmostsurfacerocks.
______..includingclimate,mineralcontent,andthepermanencyofsurfacewater,wetlandsmaybemossy,grassy,scrubby,orwoo
随机试题
以下关于责任保险合同的陈述,正确的是
青年工人,体重60kg,烧伤后半小时急诊入院,烧伤面积Ⅰ度10%、浅Ⅱ度20%、深Ⅱ度30%、Ⅲ度20%。第一个24小时预计补液量为(按国内通用公式)
肾虚导致肝虚,属于肝强导致脾弱,属于
肝郁型月经先后无定期的治法是()
A.大剂量青霉素B.淋必治C.盐酸四环素D.庆大霉素E.红霉素
债券买断式回购和质押式回购的区别是()。Ⅰ.买断式回购的初始交易中,债券持有人将债券卖给逆回购方,所有权转移至逆回购方Ⅱ.质押式回购的初始交易中,债券持有人将债券卖给逆回购方,所有权转移至逆回购方Ⅲ.买断式回购的逆回购
电子签名符合下列()条件的,视为可靠的电子签名。
某企业2008年10月份生产领用材料计划成本为200万元,月底计算出的材料成本差异率为-5%,则本月生产产品应负担的材料费用为()。
【2015河北石家庄】我国第一个实行的现代学制是_______。
若有以下程序:#includemain(){intc;c=10^5;printf("%d\n",c);}则程序的输出结果是()。
最新回复
(
0
)