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
29
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.
An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Drag your choices to the spaces where they belong. To review the passage, click on View Text.
Several theories involving the movement of continents were proposed in the nineteenth and early twentieth centuries
-
-
-
Answer Choices
A Early maps showing the coastlines of South America and Africa inspired Eduard Suess to search for fossil evidence that today’s southern continents had once been joined in a single landmass.
B To Eduard Suess, continental drift accounted for the presence of the same types of fossils on different continents that had at times been connected by land bridges.
C Du Toit’s study of the freshwater reptile Mesosaurus added to the already considerable body of evidence that Alfred Wegener had gathered in support of the idea of continental drift.
D Frank Taylor expanded on Eduard Suess’s theory of continental drift by arguing that tidal forces 100 million years ago had broken continents apart and caused the rise of the Mid-Atlantic Ridge.
E Alfred Wegener, who first developed the theory of continental drift argued that all landmasses were originally part of a supercontinent that broke up into separate continents.
F Early theories of continental drift were not widely accepted at the time because they failed to explain why continents moved.
选项
答案
B,C,E
解析
【信息归类题】本文介绍了几种关于大陆形态演变的理论。A项中所提及early maps与题干不符。D文章中并未提及10亿年。F文章中并未涉及解释大陆如何移动。因此答案是B、C、E。
转载请注明原文地址:https://kaotiyun.com/show/L5fO777K
0
托福(TOEFL)
相关试题推荐
Completethesentencesbelow.WriteNOMORETHANTHREEWORDSforeachanswer.Inthehome,oneofthemostimportantusesofwa
ChooseTWOletters,A-E.WhichTWOthingsmakethemuseumunusual?AtheguidesBtheeventsCtheanimalsDthebuildingsEthe
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.AdvertisingEffectTheimportantfactortoconsiderThe【
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.AdvertisingEffectTheimportantfactortoconsiderThe【
Completethenotesbelow.WriteNOMORETHANTWOWORDSforeachanswer.TheroleofsleepinhumansandanimalsImportanceofsl
Completethenotesbelow.WriteONEWORDONLYforeachanswer.EffectsofurbanenvironmentsonanimalsIntroductionRecenturba
ChooseTWOletters,A-E.WhichTWOsubjectsdidMartinalikebestbeforegoingtouniversity?AArtBHistoryCFrenchDEnglish
ChooseTWOletters,A-E.WhichTWOsubjectsdidMartinalikebestbeforegoingtouniversity?AArtBHistoryCFrenchDEnglish
WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.MonarchButterfliesHibernationButterflyspeciesadoptdifferent
AsystemwasdevelopedtocontroltrafficcongestionontheM25motorway.Expertsuse【L5】________informationfromthemotorw
随机试题
《我与地坛》中“她一个人在园子里走,走过我的身旁,走过我经常呆的一些地方,步履茫然又急迫”。这里使用的人物描写方法是()
脊髓灰质炎病毒的传播方式下述哪项是不可能的:()
CSA方法是
A.fss=1-e-ktB.Css=k0/kVC.X0=CssVD.dXu/dt=keXE.lg(AXu/△t)=-(k/2.303)t+lg(ke.X0)为使静脉滴注的血药浓度立即达到稳态浓度所需静脉注射的负荷剂量()。
甲于1990年与乙结婚,1991年以个人名义向其弟借款10万元购买商品房一套,夫妻共同居住。2003年,甲乙离婚。甲向其弟所借的钱,离婚时应如何处理?
竖直矩形闸门一边与水面平齐,下面有轴,已知水的密度ρ,重力加速度g,闸门高2H,闸门宽B。为阻止闸门转动需要加多大的推力F?()
背景资料:某装机容量50万kW的水电站工程建于山区河流上,拦河大坝为2级建筑物,采用碾压式混凝土重力坝,坝高为60m,坝体浇筑施工期近2年,施工导流采取全段围堰、隧洞导流的方式。施工导流相关作业内容包括:①围堰填筑;②围堰拆除;③导流隧洞开挖;④
某企业有A、B两个投资项目,计划投资额均为1000万元,其净现值的概率分布如下表所示:要求:分别计算A、B两个项目期望值的标准离差。
家住农村的小谢,父母省吃俭用供其上大学。小谢毕业后有了一份待遇不错的工作,父母年岁大了,因劳累身体也有劳损,小谢对老人悉心照顾,满足老人衣食住行等各方面的需要,看到老人腿脚不方便就买来按摩椅给老人使用。在这里,老年人享有的权益是()。
关于Kerberos和PKI两种认证协议的叙述中正确的是(58)。在使用Kerberos认证时,首先向密钥分发中心发送初始票据(59)来请求会话票据,以便获取服务器提供的服务。(59)
最新回复
(
0
)