TPO1-16听力文本V100已修订网络版3000+错误8月25日更新学习资料

1、Good is good, but better carries it.精益求精，善益求善。TPO1-16听力文本V100已修订网络版3000+错误8月25日更新新托福TPO1-16听力文本最新权威修订版ladybird老师修订了TPO1-16听力文本，订正大小问题3000多处。并对全部讲座进行了合理的分段，使其结构清晰。关注新浪微博托福SAT-ladybird老师更多原创资料请加入QQ答疑群306612832本次无老师从HYPERLINKladybird（黄晓红）老师ladybird（黄晓红）老师【TPO17-30听力文本作者】网站HYPERLINK/crysmiling/crysmilin

2、g得到资源，大幅更新了TPO听力原文。无老师根据从GTER论坛托福版HYPERLINK/bbs/forum-53-1.html/bbs/forum-53-1.html置顶帖得到的资源，对于新托福突破口听力原文进行了大幅度的更新，本次主要更新的是TPO（1-8）的听力原文，尤其是海量修正了TPO7、8两套原文之中的错误。可以说，对于各位检验自己的听力原文十分有帮助。无老师在这里同时要指出的是，这些听力原文，其实主要都是取材于早期GTER论坛的听写的成果，那是一个光辉的时代，同时也是一个快速前进的时代，当快速前进的时候，就会难以避免的出现很多疏漏，因此听力原文里面有的时候会有一些小的瑕疵，这都是难

3、以避免的，因此请各位考友们对于这份听力原文报以最大的善意！因为，这很多都是众多网友无私奉献的结果。至于这个最新版所加入的HYPERLINK/黄晓红老师的内容，可以说正确度是高于99.99%！尤其难能可贵的是，HYPERLINK/黄晓红老师听写出了无数的专业词汇，这是非常难得的，同时我们也可以想象黄晓红老师为此所付出的巨大的努力和时间，在这里替各位考友郑重感谢HYPERLINK/黄晓红老师的努力！当然，对于听写内容的校对只是这份材料的作用之一，其实还有另外一个更加重要的作用，就是对于听力试题的分析。仅仅托福考试来看，对于新托福考试的认知的准确性，大多是来自于新托福突破口TPO发布之后，因为国内的

4、众多考友们能够对于新托福考试的试题进行仔细研究的成果！在此之前一切对于这个考试的认知，其实都是一种抽象的感性的认知，因为在考场上根本没有给你留下足够的时间进行仔细反复的捉摸。因此，新托福突破口TPO起到了一个很好的，沟通考试与考生的作用。尤其需要注意的是，从现在的TPO20以后的资料我们可以发现，现在的TPO听力加入了大量的专业词汇，这就给各位考友在准备托福考试的时候加上了很大的词汇量上的难度，因此建议各位考友在准备新托福考试的时候，最好能将TPO20以后的lecture的内容挑选专业词汇比较多的进行听写，防止自己在考场上面对突然出现的专业词汇惊慌失措。听写练的是基础实力；分析错题为的是对于自

5、己做一个更有针对性的解析。要想取得一个25+的托福成绩，这两个部分的努力全都是要做的。时间苦短，刻不容缓！TOCo1-3hzuHYPERLINKl_Toc363981791TPO1PAGEREF_Toc363981791h4HYPERLINKl_Toc363981792Conversation1PAGEREF_Toc363981792h4HYPERLINKl_Toc363981793TPO1Lecture1ContemporaryartPAGEREF_Toc363981793h6HYPERLINKl_Toc363981794TPO1Lecture2GeologyPAGEREF_Toc36398

6、1794h8HYPERLINKl_Toc363981795TPO1Conversation2PAGEREF_Toc363981795h10HYPERLINKl_Toc363981796TPO1Lecture3ArcheologyPAGEREF_Toc363981796h12HYPERLINKl_Toc363981797TPO1Lecture4BiologyPAGEREF_Toc363981797h13HYPERLINKl_Toc363981798TPO2PAGEREF_Toc363981798h15HYPERLINKl_Toc363981799Conversation1PAGEREF_Toc3

7、63981799h15HYPERLINKl_Toc363981800TPO2Lecture1PsychologyPAGEREF_Toc363981800h17HYPERLINKl_Toc363981801TPO2Lecture2BotanyPAGEREF_Toc363981801h19HYPERLINKl_Toc363981802TPO2Conversation2PAGEREF_Toc363981802h20HYPERLINKl_Toc363981803TPO2Lecture3PhilosophyPAGEREF_Toc363981803h22HYPERLINKl_Toc363981804TPO

8、2Lecture4AstronomyPAGEREF_Toc363981804h23HYPERLINKl_Toc363981805TPO3PAGEREF_Toc363981805h25HYPERLINKl_Toc363981806Conversation1PAGEREF_Toc363981806h25HYPERLINKl_Toc363981807TPO3Lecture1EnvironmentalsciencePAGEREF_Toc363981807h27HYPERLINKl_Toc363981808TPO3Lecture2FilmhistoryPAGEREF_Toc363981808h29HYP

9、ERLINKl_Toc363981809TPO3Conversation2PAGEREF_Toc363981809h31HYPERLINKl_Toc363981810TPO3Lecture3ArtHistoryPAGEREF_Toc363981810h33HYPERLINKl_Toc363981811TPO3Lecture4AstronomyPAGEREF_Toc363981811h35HYPERLINKl_Toc363981812TPO4PAGEREF_Toc363981812h37HYPERLINKl_Toc363981813Conversation1PAGEREF_Toc36398181

10、3h37HYPERLINKl_Toc363981814TPO4Lecture1BiologyPAGEREF_Toc363981814h39HYPERLINKl_Toc363981815TPO4Lecture2LiteraturePAGEREF_Toc363981815h41HYPERLINKl_Toc363981816TPO4Conversation2PAGEREF_Toc363981816h43HYPERLINKl_Toc363981817TPO4Lecture3GeologyPAGEREF_Toc363981817h45HYPERLINKl_Toc363981818TPO4Lecture4

11、UnitedStatesgovernmentPAGEREF_Toc363981818h47HYPERLINKl_Toc363981819TPO-5PAGEREF_Toc363981819h49HYPERLINKl_Toc363981820Conversation1PAGEREF_Toc363981820h49HYPERLINKl_Toc363981821TPO5Lecture1SociologyPAGEREF_Toc363981821h51HYPERLINKl_Toc363981822TPO5Lecture2AstronomyPAGEREF_Toc363981822h53HYPERLINKl_

12、Toc363981823TPO5Conversation2PAGEREF_Toc363981823h55HYPERLINKl_Toc363981824TPO5Lecture3ChemistryPAGEREF_Toc363981824h57HYPERLINKl_Toc363981825TPO5Lecture4LiteraturePAGEREF_Toc363981825h59HYPERLINKl_Toc363981826TPO6PAGEREF_Toc363981826h61HYPERLINKl_Toc363981827Conversation1PAGEREF_Toc363981827h61HYPE

13、RLINKl_Toc363981828TPO6Lecture1EconomicsPAGEREF_Toc363981828h63HYPERLINKl_Toc363981829TPO6Lecture2BiologyPAGEREF_Toc363981829h65HYPERLINKl_Toc363981830TPO6Conversation2PAGEREF_Toc363981830h67HYPERLINKl_Toc363981831TPO6Lecture3CreativeWritingPAGEREF_Toc363981831h69HYPERLINKl_Toc363981832TPO6Lecture4E

14、arthSciencePAGEREF_Toc363981832h71HYPERLINKl_Toc363981833TPO7PAGEREF_Toc363981833h73HYPERLINKl_Toc363981834Conversation1PAGEREF_Toc363981834h73HYPERLINKl_Toc363981835TPO7Lecture1TheaterHistoryPAGEREF_Toc363981835h75HYPERLINKl_Toc363981836TPO7Lecture2BiologyPAGEREF_Toc363981836h77HYPERLINKl_Toc363981

15、837ListentopartofalectureinaBiologyclass.PAGEREF_Toc363981837h77HYPERLINKl_Toc363981838TPO7ConversationPAGEREF_Toc363981838h79HYPERLINKl_Toc363981839Listentoaconversationbetweenastudentandalibrarian.PAGEREF_Toc363981839h79HYPERLINKl_Toc363981840TPO7Lecture3AnthropologyPAGEREF_Toc363981840h81HYPERLIN

16、Kl_Toc363981841TPO7Lecture4GeologyPAGEREF_Toc363981841h83HYPERLINKl_Toc363981842TPO8PAGEREF_Toc363981842h84HYPERLINKl_Toc363981843Conversation1PAGEREF_Toc363981843h84HYPERLINKl_Toc363981844TPO8Lecture1AnimalBehaviorPAGEREF_Toc363981844h86HYPERLINKl_Toc363981845TPO8Lecture2ArtHistoryPAGEREF_Toc363981

17、845h88HYPERLINKl_Toc363981846TPO8Conversation2PAGEREF_Toc363981846h90HYPERLINKl_Toc363981847TPO8Lecture3HistoryPAGEREF_Toc363981847h92HYPERLINKl_Toc363981848TPO8Lecture4ChemistryPAGEREF_Toc363981848h93HYPERLINKl_Toc363981849TPO9PAGEREF_Toc363981849h95HYPERLINKl_Toc363981850Conversation1PAGEREF_Toc36

18、3981850h95HYPERLINKl_Toc363981851TPO9Lecture1TheaterPAGEREF_Toc363981851h96HYPERLINKl_Toc363981852TPO9Lecture2EnvironmentalSciencePAGEREF_Toc363981852h98HYPERLINKl_Toc363981853TPO9Conversation2PAGEREF_Toc363981853h100HYPERLINKl_Toc363981854TPO9Lecture3GeologyPAGEREF_Toc363981854h102HYPERLINKl_Toc363

19、981855TPO9Lecture4LinguisticPAGEREF_Toc363981855h104HYPERLINKl_Toc363981856TPO10PAGEREF_Toc363981856h106HYPERLINKl_Toc363981857Conversation1PAGEREF_Toc363981857h106HYPERLINKl_Toc363981858TPO10Lecture1MarineBiologyPAGEREF_Toc363981858h108HYPERLINKl_Toc363981859TPO10Lecture2EuropeanHistoryPAGEREF_Toc3

20、63981859h110HYPERLINKl_Toc363981860Conversation2PAGEREF_Toc363981860h112HYPERLINKl_Toc363981861TPO10Lecture3EcologyPAGEREF_Toc363981861h114HYPERLINKl_Toc363981862TPO10Lecture4PsychologyPAGEREF_Toc363981862h116HYPERLINKl_Toc363981863TPO11PAGEREF_Toc363981863h117HYPERLINKl_Toc363981864Conversation1PAG

21、EREF_Toc363981864h117HYPERLINKl_Toc363981865TPO11Lecture1BiologyPAGEREF_Toc363981865h120HYPERLINKl_Toc363981866TPO11Lecture2ArchitecturePAGEREF_Toc363981866h122HYPERLINKl_Toc363981867TPO11Conversation2PAGEREF_Toc363981867h125HYPERLINKl_Toc363981868TPO11Lecture3EnvironmentalsciencePAGEREF_Toc36398186

22、8h128HYPERLINKl_Toc363981869TPO11Lecture4BusinessPAGEREF_Toc363981869h131HYPERLINKl_Toc363981870TPO12PAGEREF_Toc363981870h133HYPERLINKl_Toc363981871Conversation1PAGEREF_Toc363981871h133HYPERLINKl_Toc363981872TPO12Lecture1BiologyPAGEREF_Toc363981872h135HYPERLINKl_Toc363981873TPO12Lecture2BusinessPAGE

23、REF_Toc363981873h136HYPERLINKl_Toc363981874TPO12Conversation2PAGEREF_Toc363981874h139HYPERLINKl_Toc363981875TPO12Lecture3MusichistoryPAGEREF_Toc363981875h142HYPERLINKl_Toc363981876TPO12Lecture4EnvironmentalsciencePAGEREF_Toc363981876h144HYPERLINKl_Toc363981877TPO13PAGEREF_Toc363981877h146HYPERLINKl_

24、Toc363981878Conversation1PAGEREF_Toc363981878h146HYPERLINKl_Toc363981879TPO13Lecture1CityplanningPAGEREF_Toc363981879h149HYPERLINKl_Toc363981880TPO13Lecture2EcologyPAGEREF_Toc363981880h151HYPERLINKl_Toc363981881TPO13Conversation2PAGEREF_Toc363981881h154HYPERLINKl_Toc363981882TPO13Lecture3PoetryPAGER

25、EF_Toc363981882h156HYPERLINKl_Toc363981883TPO13Lecture4AstronomyPAGEREF_Toc363981883h159HYPERLINKl_Toc363981884TPO14PAGEREF_Toc363981884h161HYPERLINKl_Toc363981885Conversation1PAGEREF_Toc363981885h161HYPERLINKl_Toc363981886TPO14Lecture1PsychologyPAGEREF_Toc363981886h163HYPERLINKl_Toc363981887TPO14Le

26、cture2BiologyPAGEREF_Toc363981887h165HYPERLINKl_Toc363981888TPO14Conversation2PAGEREF_Toc363981888h167HYPERLINKl_Toc363981889TPO14Lecture3AstronomyPAGEREF_Toc363981889h170HYPERLINKl_Toc363981890TPO14Lecture4ArcheologyPAGEREF_Toc363981890h172HYPERLINKl_Toc363981891TPO15PAGEREF_Toc363981891h174HYPERLI

27、NKl_Toc363981892Conversation1PAGEREF_Toc363981892h174HYPERLINKl_Toc363981893TPO15Lecture1PsychologyPAGEREF_Toc363981893h176HYPERLINKl_Toc363981894TPO15Lecture2GeologyPAGEREF_Toc363981894h178HYPERLINKl_Toc363981895TPO15Conversation2PAGEREF_Toc363981895h180HYPERLINKl_Toc363981896TPO15Lecture3ArtHistor

28、yPAGEREF_Toc363981896h182HYPERLINKl_Toc363981897TPO15Lecture4BiologyPAGEREF_Toc363981897h184HYPERLINKl_Toc363981898TPO16PAGEREF_Toc363981898h187HYPERLINKl_Toc363981899Conversation1PAGEREF_Toc363981899h187HYPERLINKl_Toc363981900TPO16ScriptLecture1PAGEREF_Toc363981900h189HYPERLINKl_Toc363981901TPO16Sc

29、riptLecture2PAGEREF_Toc363981901h191HYPERLINKl_Toc363981902TPO16ScriptConversation2PAGEREF_Toc363981902h193HYPERLINKl_Toc363981903TPO16ScriptLecture3PAGEREF_Toc363981903h195HYPERLINKl_Toc363981904TPO16ScriptLecture4PAGEREF_Toc363981904h196TPO1Conversation1NarratorListentopartofaconversationbetweenas

30、tudentandalibrarian.StudentHi,um,Ireallyhopeyoucanhelpme.LibrarianThatswhyImhere.WhatcanIdoforyou?StudentImsupposedtodoaliteraturereviewformypsychologycourse,butImhavingahardtimefindingarticles.Idontevenknowwheretostartlooking.LibrarianYousaidthisisforyourpsychologycourse,right?SoyourfocusisonStuden

31、tDreamInterpretation.LibrarianWell,youhaveafocus,sothatsalreadyagoodstart.Hmmmwell,therereafewthingsohwaithaveyoucheckedtoseeifyourprofessorputanymaterialforyoutolookatonreserve?StudentAha,thatsonethingIdidknowtodo.Ijustcopiedanarticle,butIstillneedthreemoreonmytopicfromthreedifferentjournals.Librar

32、ianLetsgetyougoingonlookingforthosethen.WehaveprintedversionsoftwentyorsopsychologyjournalsintheReferenceSection.Theseareonespublishedwithinthelastyear.NowthatIthinkaboutittheresajournalnamedSleepandDreams.StudentOh,yeah,thearticleIjustcopiedisfromthatjournal,soIvegottolookinothersources.LibrarianOk

33、,actually,mostofourmaterialsareavailableelectronicallynow.Youcanaccesspsychologydatabasesorelectronicjournalsandarticlesthroughthelibraryscomputers,andifyouwanttosearchbytitlewiththeworddreamforexample,justtypeitinandallthearticleswithdreaminthetitlewillcomeuponthescreen.StudentCool,thatsgreat!Tooba

34、dIcannotdothisfromhome.LibrarianButyoucan.Allofthelibrarysdatabasesandelectronicsourcescanbeaccessedthroughanycomputerconnectedtotheuniversitynetwork.StudentReally?!IcantbelieveIdidntknowthat.Itstillsoundslikeitsgoingtotakeawhilethough,youknow,goingthroughallofthatinformation,allofthosesources.Libra

35、rianMaybe,butyoualreadynarrowedyoursearchdowntoarticlesonDreamInterpretation,soitshouldntbetoobad.Andyouprobablynoticethattheresanabstractorsummaryatthetopofthefirstpageofthearticleyoucopied.Whenyougointothedatabasesandelectronicsources,youhavetheoptiontodisplaytheabstractsonthecomputerscreen,skimmi

36、ngthosetodecidewhetherornotyouwanttoreadthewholearticleshouldcutdownsometime.StudentRight,abstracts!Theylldefinitelymaketheprojectmoredoable.IguessIshouldtryouttheelectronicsearchwhileImstillherethen,youknow,justincase.LibrarianSure,erthatcomputersfreeoverthere,andIllbeheretillfivethisafternoon.Stud

37、entThanks,Ifeelalotbetteraboutthisassignmentnow.TPO1Lecture1ContemporaryartListentopartofalectureinacontemporaryartclass.ProfessorOk,Imgoingtobeginthislecturebygivingyouyournextassignment.RememberIsaidthatatsomepointduringthissemesterIwantedyoutoattendanexhibitattheFairyStreetGalleryandthenwriteabou

38、tit?Well,theexhibitthatIwantyoutoattendiscomingup.Itsalreadystartedinfact,butitllbeatthegalleryforthenextmonth,whichshouldgiveyouplentyoftimetocompletethisassignment.ThenameoftheartistexhibitingthereisRoseFrantzen.Frantzensworkmaybeunfamiliartoyousinceshesarelativelyyoungartist.Butshesgotaveryunusua

39、lstyle,comparedtosomeoftheartistswevelookedatthisterm.Butanyway,FrantzensstyleiswhatsheherselfcallsRealisticImpressionism.Soyouveprobablystudiedbothofthesemovementsseparately,separatemovements,RealismandImpressionism,insomeofyourarthistorycourses.Sowhocanjustsumtheseup?StudentWell,Impressionismstart

40、edinthelate19thcentury.Umthebasicimpressioniststylewasverydifferentfromearlierstyles.Itdidntdepictscenesormodelsexactlyastheylooked.UmImpressionistpainterstendedtoapplypaintreallythickly,andinbigbrushstrokes,sothetextureofthecanvaswasrough.ProfessorGood.Whatelse?Whatwerethesubjects?StudentWell,aloto

41、fimpressionistartistspaintedeverydayscenes,likepeopleonthestreetsandincafes,uh,lotsofnaturescenes,especiallylandscapes.ProfessorGood.Sowhenyougototheexhibit,Ireallywantyoutotakeacloselookatacertainpainting.Itsafarmscene.Andyouwillseeitrightasyouenterthegallery.ThereasonIthinkthispaintingissoimportan

42、tisthatitstressestheimpressionistaspectofFrantzensstyle.Itsanoutdoorscene,aneverydayscene.Itskindofbleak,butyoucanreallyseethosebroadbrushstrokesandtheblurrylines.Thecolorsarentquiterealistic.Theskyiskindof,wellanunnaturalpinkishyellow.Andthefenceintheforegroundisblue,butsomehowtheoverallscenegivesa

43、nimpressionofacold,bleakwinterdayonafarm.Sothatstheimpressionistsideofherwork.Oh,andspeakingaboutfarms,thatremindsme.OneinterestingthingIreadaboutFranztenisthatwhenshefirstmovedbacktoIowaafterlivingabroad,sheoftenvisitedthisplaceinhertowncalledtheSalesBarn.AndtheSalesBarn,itwasbasicallythisplacewher

44、ethelocalfarmersboughtandsoldtheircattle,theirfarmanimals.AndthereasonFrantzenwentthere,andshelateronwouldvisitotherplaceslikedancehalls,wastoobservepeopleandthewaysthattheymoved.Shereallyfoundthatthishelpedherworkthatitgaveheranunderstandingofbodymovementsandactions,howhumansmove,andstandstill,what

45、theirpostureswerelike,too.So,whataboutRealism?WhataretheelementsofRealismweshouldbelookingforinFrantzenswork?StudentUmrealhonestdepictionsofsubjectmatter,prettyunidealizedstuff,andprettyeverydaysubjectmatter,too.ProfessorGood.OneotherpaintingIreallywantyoutolookatisofayoungwomansurroundedbypumpkins.

46、Youwillnoticethatthewomansfaceissorealisticlookingthatitsalmostlikeaphotograph.Thewomansnoseisalittlelessthanperfectandherhairiskindofmessedup.Thisisrealism.Butthen,thebackgroundofthepainting,thiswomanwiththepumpkinsiswrappedinablanketofbroadthickbrushstrokes,and,itsallkindsofzigzaggingbrushstrokesa

47、ndlines,kindofchaoticalmostwhenyoulookatitclose.Andtherearevibrantcolors.Thereslotsoforange,withlittlehintsofanelectricbluepeekingout.IfindFrantzentobeaveryaccessibleartist.Imean,someartists,toappreciatethem,youhavetoknowtheirlifestory.ButheresalittlebitaboutRoseFrantzenslifeanyway.Sheattendedartsch

48、ool,butwastoldbyoneofherinstructorsthatshewasnotgoodatillustration,thatsheshouldgointoadvertisinginstead.Soshetookadvertisingclassesandfineartsclassestoo,untilshewasconvincedbytheheadofanadvertisingagencythatherworkwasreallygood,thatshecouldbeanartist.Butofcourse,itsnotaseasyasthat,andsoFrantzenhadt

49、opaintotherpeoplesportraitsatplaceslikeartfairsjusttomakemoneytobuypaintforhermoreseriousartwork.Nomatterwhat,sheneverstoppedpainting.Andnow,Frantzenisdoingextremelywell.Andherworkisbeingshownalloverthecountry.SoIthinkmostofuswouldbediscouragedifwehadtofacechallengesanddifficultieslikethat.Butwhatsi

50、mportantisthatyoukeepatitthatyoudontgiveup.Thatswhatisreallyimportanttoremember.TPO1Lecture2GeologyListentopartofalectureinageologyclass.ProfessorOk,letsgetstarted.Great.TodayIwanttotalkaboutawayinwhichweareabletodeterminehowoldapieceofland,orsomeothergeologicfeatureis-datingtechniques.Imgoingtotalk

51、aboutaparticulardatingtechnique.Why?Gooddatingiskeytogoodanalysis.Inotherwords,ifyouwanttoknowhowalandformationwasformed,thefirstthingyouprobablywanttoknowishowolditis.Itsfundamental.UhTaketheGrandCanyonforinstance.Now,wegeologiststhoughtwehadaprettygoodideaofhowtheGrandCanyoninthesouthwesternUnited

52、Stateswasformed.Weknewthatitwasformedfromsandstonethatsolidifiedsomewherebetween150and300millionyearsago.Beforeitsolidified,itwasjustregularsand.Essentiallyitwaspartofavastdesert.Anduntiljustrecently,mostofusthoughtthesandhadcomefromanancientmountainrangefairlyclosebythatflattenedoutovertime.Thatsbe

53、entheconventionalwisdomamonggeologistsforquitesometime.Butnowwevelearnedsomethingdifferent,andquitesurprising,usingatechniquecalledUranium-LeadDating.IshouldsaythatUranium-LeadDatinghasbeenaroundforquiteawhile.Buttherehavebeensomerecentrefinements.Iwillgetintothisinaminute.Anyway,Uranium-LeadDatingh

54、asproducedsomesurprises.TwogeologistsdiscoveredthatabouthalfofthesandfromtheGrandCanyonwasactuallyoncepartoftheAppalachianMountains.Thatsreallyeye-openingnews,sincetheAppalachianMountainRangeis,ofcourse,thousandsofkilometerstotheeastoftheGrandCanyon.Soundsprettyunbelievable,right?Ofcourse,theobvious

55、questionishowdidthatsandendupsofarwest?Thetheoryisthathugeriversandwindcarriedthesandwestwhereitmixedinwiththesandthatwasalreadythere.Well,thiswasaprettyrevolutionaryfinding.UmanditwasbasicallybecauseofUranium-LeadDating.Why?Well,aseveryoneinthisclassshouldknow,weusuallylookatthegraintypewithinsands

56、tone,meaningtheactualparticlesinthesandstone,todeterminewhereitcamefrom.Youcandootherthingstoo,likelookatthewindorwaterthatbroughtthegrainstotheirlocationandfigureoutwhichwayitwasflowing.Butthatsonlyusefuluptoapoint,andthatsnotwhatthesetwogeologistsdid.Uranium-LeadDatingallowedthemtogoaboutitinanent

57、irelydifferentway.Whattheydidwas:theylookedatthegrainsofZirconinthesandstone.ZirconisamaterialthatcontainsradioactiveUranium,whichmakesitveryusefulfordatingpurposes.Zirconstartsoffasmoltenmagma,thehotlavafromvolcanoes.Thismagmathencrystallizes.AndwhenZirconcrystallizes,theUraniuminsideitbeginstochan

58、geintoLead.SoifyoumeasuretheamountofLeadintheZircongrain,youcanfigureoutwhenthegrainwasformed.Afterthat,youcandeterminetheageofZirconfromdifferentmountainranges.Onceyoudothat,youcancomparetheageoftheZirconinthesandstoneinyoursampletotheageoftheZirconinthemountains.IftheageoftheZirconmatchestheageofo

59、neofthemountainranges,thenitmeansthesandstoneactuallyusedtobepartofthatparticularmountainrange.Iseverybodywithmeonthat?Good.So,inthiscase,Uranium-LeadDatingwasusedtoestablishthathalfofthesandstoneinthesampleswasformedatthesametimethegraniteintheAppalachianMountainswasformed.Sobecauseofthis,thisnewwa

60、yofdoingUranium-LeadDating,wevebeenabletodeterminethatoneofourmajorassumptionsabouttheGrandCanyonwaswrong.LikeIsaidbefore,Uranium-LeadDatinghasbeenwithusforawhile.But,umuntilrecently,inordertodoit,youreallyhadtostudymanyindividualgrains.Andittookalongtimebeforeyougotresults.Itjustwasntveryefficient.