大学新概念英语阅读(一 )

大学新概念英语阅读（一）【篇一】PlateTectonicsandSea-floorSpreadingThetheoryofplatetectonicsdescribesthemotionsofthelithosphere,thecomparativelyrigidouterlayeroftheEarththatincludesallthecrustandpartoftheunderlyingmantle.Thelithosphereisdividedintoafewdozenplatesofvarioussizesandshapes,ingeneraltheplatesareinmotionwithrespecttooneanother.Amid-oceanridgeisaboundarybetweenplateswherenewlithosphericmaterialisinjectedfrombelow.Astheplatesdivergefromamid-oceanridgetheyslideonamoreyieldinglayeratthebaseofthelithosphere.SincethesizeoftheEarthisessentiallyconstant,newlithospherecanbecreatedatthemid-oceanridgesonlyifanequalamountoflithosphericmaterialisconsumedelsewhere.Thesiteofthisdestructionisanotherkindofplateboundary：asubductionzone.Thereoneplatedivesundertheedgeofanotherandisreincorporatedintothemantle.Bothkindsofplateboundaryareassociatedwithfaultsystems,earthquakesandvolcanism,butthekindsofgeologicactivityobservedatthetwoboundariesarequitedifferent.Theideaofsea-floorspreadingactuallyprecededthetheoryofplatetectonics.Initsoriginalversion,intheearly1960’s,itdescribedthecreationanddestructionoftheoceanfloor,butitdidnotspecifyrigidlithosphericplates.ThehypothesiswassubstantiatedsoonafterwardbythediscoverythatperiodicreversalsoftheEarth’smagneticfieldarerecordedintheoceaniccrust.Asmagmarisesunderthemid-oceanridge,ferromagneticmineralsinthemagmabecomemagnetizedinthedirectionofthegeomagneticfield.Whenthemagmacoolsandsolidifies,thedirectionandthepolarityofthefieldarepreservedinthemagnetizedvolcanicrock.ReversalsofthefieldgiverisetoaseriesofmagneticstripesrunningparalleltotheaxisoftheTheoceaniccrustthusservesasamagnetictaperecordingthehistoryofthegeomagneticfieldthatcanbedatedindependently;thewidthofthestripesindicatestheratethesea-floorspreading.板块结构与海床扩展板块结构理论描述岩石圈的运动。岩石圈是相对坚硬的地球外层，包括全部地壳和部分地幔。岩石圈被划分为几十个大小不同形状各异的板块，一般来说这些板块都处于相对运动之中。一道中海脊是板块之间的边界，在那里新的岩石圈的物质从下部注入。当板块从中海脊脱离时，它们滑向在岩石圈基部较易变形的地层上。因为地球的大小本质上是不变的，只有同等数量的岩石圈物质在其它地方被吞没，新的岩石圈才能生成。销毁旧岩石圈的地方形成另外一种板块边界：一块潜没的区域。在这里，一块板块潜没到另一板块的边缘之下并结合入地幔之中。两种板块边界均与地层系统、地震以及火ft活动相关，但在两种边界处观察到的诸般地质活动却迥然不同。2060轴线平行的条形磁区。这样海洋壳就扮演了磁带的角色，记录下能够鉴定时间的地磁场的历史。条形磁区的宽度表明了海底扩展的速度。【篇三】OilRefiningAnimportantnewindustry,oilrefining,grewaftertheCivilwar.Crudeoil,orpetroleum–adark,thickoozefromtheearth–hadbeenknownforhundredsofyears,butlittleusehadeverbeenmadeofit.Inthe1850sSamuelM.Kier,amanufacturerinwesternPennsylvania,begancollectingtheoilfromlocalseepagesandrefiningitintokerosene.Refining,likesmelting,isaprocessofremovingimpuritiesfromarawmaterial.Kerosenewasusedtolightlamps.Itwasacheapsubstituteforwhaleoil,whichwasbecominghardertoget.Soontherewasalargedemandforkerosene.Peoplebegantosearchfornewsuppliesofpetroleum.ThefirstoilwellwasdrilledbyE.L.Drake,aretiredrailroadconductor.In1859hebegandrillinginTitusville,Pennsylvania.Thewholeventureseemedsoimpracticalandfoolishthatonlookerscalledit"DrakesFolly".Butwhenhehaddrilleddownabout70feet(21meters),DrakestruckHiswellbegantoyield20barrelsofcrudeoiladay.NewsofDrakessuccessbroughtoilprospectorstothescene.Bytheearly1860’sthesewildcatterswerefor"blackgold"alloverwesternPennsylvania.TheboomrivaledtheCaliforniagoldrushof1848initsexcitementandWildWestatmosphere.Anditbroughtfarmorewealthtotheprospectorsthananygoldrush.Crudeoilcouldberefinedintomanyproducts.Forsomekerosenecontinuedtobetheprincipalone.Itwassoldingrocerystoresanddoor-to-door.Inthe1880srefinerslearnedhowtomakeotherpetroleumproductssuchaswaxesandlubricatingoils.Petroleumwasnotthenusedtomakegasolineorheatingoil.【篇四】译文炼油一种重要的新兴工业——炼油业在国内战争后成长起来。未加工的石油，或原油——一种深色的地下的稠浆——数百年来一直为大众所知，但是人们却很少使用过它。在十九世纪五十年代，萨缪尔·M·科尔，宾西法尼亚西部的一位制造商，开始从当地的溢出物中收集石油并将它炼成煤油