文本内容:
William Smith威廉•史密斯In1769in alittle townin Oxfordshire,England,a childwith thevery ordinarynameof WilliamSmith wasborn intothe poorfamily ofa villageblacksmith.He receivedrudimentaryvillage schoolingbut mostlyhe roamedhis unclesfarm collectingthe fossilsthatwere soabundant in the rocksof theCotswold hills.When hegrew older,WilliamSmith taughthimself surveyingfrom bookshe boughtwith hissmall savingsand atthe ageofeighteen he was apprenticedto asurveyor of the localparish.He thenproceeded toteachhimself geologyand whenhewastwenty-four,he wentto workfor thecompany thatwasexcavating theSomerset CoalCanal in the southof England.1769年,在英国牛津郡的一个小镇上,一个小男孩儿出生在村里一户穷铁匠家,他的名字很普通,叫做威廉•史密斯史密斯只在村里的学校接受了最基本的教育,他大部分的时间都是在叔叔的农场里搜寻化石,这些化石在科茨沃尔德山的岩石里是很常见的长大后,他开始用微薄的积蓄买书自学测量,18岁的时候,史密斯成为了当地教区测量员的助理后来,他又自学了地质学,24岁时,他开始为挖掘英格兰南部Somerset Coal运河的一家公司工作This wasbefore thesteam locomotive,and canalbuilding wasat itsheight.Thecompanies buildingthe canalsto transportcoal neededsurveyors tohelp themfind thecoaldeposits worthmining aswell asto determinethe bestcourses forthe canals.This jobgaveSmith anopportunity tostudy thefresh rockoutcrops createdby thenewly dugcanal.Helater workedon similarjobs acrossthe lengthand breadthof England all thewhile studyingthenewly revealedstrata andcollecting all the fossilshe couldfind.Smith usedmailcoaches totravel asmuch as10,00miles peryear.In1815he publishedthe firstmoderngeological map“A MapoftheStrata ofEngland andWales witha Partof Scotland”,mapso meticulouslyresearched thatit canstill beused today.那是在蒸汽火车发明之前,运河建设正处于顶峰时期致力于开掘运河来运输煤的公司需要测量员帮助他们探寻值得挖掘的煤矿的地址以及最佳的运河路线这份工作为史密斯提供了机会,使他能够接触和学习那些因为运河开掘而露出地面的新鲜岩层后来他仍从事类似的工作,行遍全国,不断地研究那些新出现的地层,同时收集他所能发现的化石史密斯乘着邮件马车每年行进将近1万英里1815年,他绘制了第一张现代地质学地图——《英格兰、威尔士及部分苏格兰地区地层地图》,这张地质地图绘制得非常精确,直到现在仍有参考价值In1831when Smithwas finallyrecognized bythe GeologicalSociety ofLondon as,the fatherof Englishgeology wasnot onlyfor hismaps butalso fbrsomething evenmoreimportant.Ever sincepeople hadbegun tocatalog the strata inparticular outcrops,there hadbeen thehope that these couldsomehow beused tocalculate geologicaltime.Butas more and moreaccumulations ofstrata werecataloged in moreandmore places,itbecame clearthatthesequences ofrocks sometimesdiffered fromregion toregion andthatno rocktype wasever goingto becomea reliabletime markerthroughout theworld.Evenwithout theproblem ofregional differences,rocks presenta difficultyas uniquetimemarkers.Quartz isquartz—a siliconion surroundedby fouroxygen ions-theres nodifferenceat allbetween two-million-year-old Pleistocenequartz andCambrian quartzcreatedover500million yearsago.1831年,史密斯最终被伦敦地质学会认可,并赋予他“英国地质学之父”的称号,这不仅仅是因为那张地图,同时也是为了其他更重要的原因从人们开始对露出地面的特殊岩层进行分类的时候越大家就开始认为这些岩石可能会以某种方式被用于计算地质年代但是,随着各地越来越多的岩层的积累和分类,岩层顺序也因地区的不同而不同,因此,全世界没有一种特定的岩层能被认作是划分地质年代的标志即便排除区域差异的影响,岩石作为确定年代的标记还是存在一些难题石英就是石英——四个氧离子包围一个硅离子的化合物——而200万年前更新世的石英和5亿年前寒世纪的石英并无差别As hecollected fossilsfrom stratathroughout England,Smith beganto seethat thefossilstold adifferent storyfrom the rocks.Particularly in the youngerstrata therocks wereoftenso similarthat hehad troubledistinguishing thestrata,but henever hadtrouble tellingthe fossils apart.While rockbetween twoconsistent stratamight inone placebe shaleandin anothersandstone,the fossilsin thatshale orsandstone werealways thesame.Somefossils enduredthrough somany millionsof yearsthat theyappear Inmany strata,butothers occuronly ina fewstrata,andafew specieshad theirbirths andextinctions withinoneparticular stratum.Fossils arethus identifyingmarkers forparticular periodsin Earthshistory.史密斯在全英国的岩层中不断搜集化石,后来他发现化石所反映的史实和岩石反映的完全不同,尤其是那些新产生的地层里的岩石,这些岩石非常类似,不易于区分地层而区分其中的化石对史密斯来说简直就是轻而易举在同一地层中发现的岩石可能在这片地层中属于泥板岩,而在另一片地层中可能是砂岩,而在那些泥板岩或者砂岩中的化石往往都是一样的有的化石经历了数百万年之久,它们存在于很多岩层中,但有的化石只存在于部分地层,还有一部分生物的化石从出现至灭绝都只出现在一个特定的岩层中因此,化石才是真正划分地球历史特定年代的指针Not onlycould Smithidentify rockstrata bythe fossilsthey contained,he couldalsosee apattern emerging:certain fossilsalways appearinmoreancient sediments,whileothers beginto beseen asthestratabecome morerecent.■By followingthefossils,Smithwas ableto putallthestrata ofEnglands earthinto relativetemporal sequence.■About thesametime,Georges Cuviermade thesame discoverywhile studyingtherocksaround Paris.■Soon itwas realizedthat thisprinciple offaunal animalsuccession wasvalid notonly inEnglandor Francebut virtuallyeverywhere.■It wasactually aprinciple offloralsuccession aswell,because plantsshowed thesame transformationthrough timeas didfauna.Limestone maybe foundinthe Cambrian or-300million yearslater-intheJurassicstrata buta trilobite一the ubiquitousmarine arthropodthat hadits birthintheCambrian—will neverbe foundin Jurassicstrata,nor adinosaur intheCambrian.史密斯不仅可以通过岩石中包含的化石来识别地层,而且可以看出它们显露出来的模式一些特定的化石往往出现在更为久远的沉积物当中,而其他的化石则可以在距今年代较近的地层中发现通过追踪化石,史密斯将英国范围内所有的地层按照出现时间进行了排序同时,乔治•居维叶在研究巴黎周围的岩石时也得出了同样的发现很快人们就开始认识到,这种动物物种的延续性是符合逻辑的,不仅仅是在英国、法国,而且几乎在全世界范围都是适用的事实上,这一原则同样适用于证实植物的延续性,因为植物和动物一样,它们的化石也显示了时间的推移人类有可能在侏罗纪时期的地层中发现寒世纪或者3亿年后的石灰岩,但绝不可能在侏罗纪时期地层中发现三叶虫化石(三叶虫是寒世纪非常普遍的水生节肢动物),也不可能发现寒世纪时期的恐龙化石。