工程地質(zhì)課件

Introduction

緒論

1thedefinitionofcivilengineeringgeology

土木工程地質(zhì)的基本概念

2Thepositionofengineeringgeologyinthecivilengineeringcoursesystem(

工程地質(zhì)在土木學(xué)科體系中的位置)3themainsubstanceaboutengineeringgeology(工程地質(zhì)學(xué)研究的具體內(nèi)容)

4theimportanceofGE(學(xué)習(xí)意義)5Demands(requirements)（要求）Themaintopicsinintroduction

緒論中的主要內(nèi)容thedefinitionofengineeringgeology

（工程地質(zhì)學(xué)的基本概念）

(1)Engineeringgeologyisaboutapplyingallbranchesofthegeosciences(地質(zhì)學(xué))toassurethesafety,efficiency,andeconomyofengineeringandenvironmentalprojects.

（2）EngineeringGeologyisdevotedtotheinvestigation（勘察）,studyandsolutionoftheengineeringandenvironmentalproblemswhichmayariseastheresultoftheinteractionbetweengeologyandtheworksandactivitiesofmanaswellastothepredictionandthedevelopmentofmeasuresforpreventionormediationofgeologicalhazards（地質(zhì)災(zāi)害）(3)Whicharemainlyconcernedwiththegeologicalproblemsencounteredincivilengineering.Itsmaintasksistoinvestigateandevaluatethegeologicalengineeringproblems,providethebasicinformationfortheplan,designandconstructionofthecivilengineering.2Thepositionofengineeringgeologyinthecivilengineeringcoursesystem(

工程地質(zhì)在土木學(xué)科體系中的位置Corecourse（基礎(chǔ)課程）

→

Differentialandintegral→algebra→probabilityandstatistics

→

engineeringmath→Physics→ChemicalTechnologicalcorecourse（專業(yè)基礎(chǔ)課程）

→

Surveying→engineeringmapping→materials→surveying

→

engineering（工程測量）

→engineeringgeology(工程地質(zhì))→soil(rock)mechanics（巖土力學(xué)）

→

theoreticalmechanics→materialmechanics→structuremechanics→elasticorplastic（彈塑性）

→hydrolicmechanics（水力學(xué)）Specializedcourse（專業(yè)課程）

→concretestructure（砌體結(jié)構(gòu)

→steelstructure（鋼結(jié)構(gòu)）

→roadengineering（道路工程）

→thedesignofroadsurvey（道路勘測設(shè)計(jì)）→bridgeengineering(橋樑工程)→trafficengineering(交通工程)→foundationengineering(基礎(chǔ)工程)→constructiontechnology(building…)施工技術(shù)→engineeringmanagementandbudgetestimation→engineeringbiddingrehabilitation(building、brigde、road…)（工程招投標(biāo)）3themainsubstanceaboutengineeringgeology(工程地質(zhì)學(xué)研究的具體內(nèi)容)ThepurposeofstudyingGEistoprovidegoodgeologicalenvironmentforengineeringortoevaluateandforecasttheengineeringgeologicalproblemsthatmayoccurredintheperiodoftheservicetime（服務(wù)期）ofthebuilding.onthisbase,togivetheeffectiveengineeringpreventionmethods.◆thestudyabouttopographyandlandforms

（地形地貌）◆thestudyaboutthefundamentalengineering

properties(physicalandmechanics)ofsoilsandrock(巖土工程性質(zhì)）◆geologicalstructure（地質(zhì)構(gòu)造）

GeologicalEnvironment(GeologicalCondition)

地質(zhì)環(huán)境和地質(zhì)條件的含義4theimportanceofGE(學(xué)習(xí)意義)◆hydrogeology(水文地質(zhì)：地下水條件)◆theanalysesofengineeringgeologicalproblems

（工程地質(zhì)問題分析）

◆theengineeringinvestigation（工程勘察）5Demands(requirements)（要求）1tomasterthebasicconceptaboutEG2tocomprehendthemaingeologicalproblemsoccurredinengineering.knowingthathowtheproblemshappened,howcanwepreventit.3classdiscipline4finishthehomeworkontimeChapter1Thebasicinformationofearth

第一章地球的基本知識SECTION1-1Innerstructureofearth

第一節(jié)地球的內(nèi)部結(jié)構(gòu)

ThisregionisthincomparedtotheotherlayersintheEarth.

Itvariesinthicknessfrom10kmdeepto65kmdeep.

Thecrustismadeupoflighterrocksthat"float"ontopofthemantle.

This

layerincludesthecontinentsaswellastherockundertheoceans.

wehavebuiltmanydeepminesbutNONEhaveyetreachedthemantle!TheCrust(地殼)軟流圈巖石圈上地慢有關(guān)巖石圈(lithosphere)StructureoftheEarth‘scrustandtopmostlayeroftheuppermantle（上地慢）.Thelithosphere（巖石圈）consistsoftheoceaniccrust,continentalcrust,anduppermostmantle.Beneaththelithosphereistheasthenosphere（軟流圈）.Thislayer,whichisalsopartoftheuppermantle,extendstoadepthofabout200kilometers.Sedimentarydepositsarecommonlyfoundattheboundariesbetweenthecontinentalandoceaniccrust.Thisregionliesunderthecrustandisapproximately2900kmthick.

Themantleismuchdenserthanthecrust(whichiswhythecrustfloatsontop)andhasatexturemuchliketar.

Therockinthisregionisrichincompoundsmadefromiron,magnesium,andsiliconwhichaccountsforwhyitisdenserthanthecrust.TheMantle（地幔）Thisregionisdividedintotwoparts.

TheouterpartiscalledtheOuterCore.

Itisabout2100kmthickandmadeofliquidnickelandiron.

TheinnerpartiscalledtheInnerCoreanditistherealcentreoftheEarth.

Thispartisabout2800kmindiameterandismadeofsolidironandnickel.TheCore:SECTION1-2PlateStructureTheory

第二節(jié)板塊構(gòu)造理論1PacificPlate(太平洋板塊)

2NorthAmericanPlate（北美板塊）

3SouthAmericanPlate

（南美板塊）4EurasianPlate（歐亞板塊）

5AfricanPlate（非洲板塊）

6IndoAustralianPlate（澳印板塊）

7AntarcticPlate（南極州板塊）

1PacificPlate2NorthAmericanPlate

3SouthAmericanPlate4EurasianPlate

5AfricanPlate6IndoAustralianPlate

7AntarcticPlate

板塊構(gòu)造理論板塊的形成（大陸漂移）德國氣象學(xué)家阿爾弗雷德·魏格納（AlfredWegener）

海底擴(kuò)張理論（TheoryofOceanFloorSpreading）海底擴(kuò)張的證據(jù)（沉積物的年齡）海底擴(kuò)張的結(jié)果（喜馬拉雅山的形成）

海溝的形成巖石迴圈的概念SECTION1-3:TheconceptofGeologicalAction（function）第三節(jié)地質(zhì)作用的概念1Whatisgeologicalaction（基本定義）

meantheactionsthatmakealterationforthecomposition，structure,shapeoftherockcyclebecauseofthenaturaldynamics.

CrustmovementSunnaturaldynamicsWindglaciergravitationwater2

TheclassificationoftheGeo.Action

（地質(zhì)作用分類）

(1)

outer-dynamicsgeologicalaction(外動(dòng)力地質(zhì)作用)

dynamicsourceisfromthesun,gravity,attractionforcebetweensunandmoon.

?Weathering（風(fēng)化作用）

→theRockisdestroyedattheplacewhereitwasformedbecauseoftheouterdynamics.

?Erosion（剝蝕作用）

→Rockbody巖體isseparatedfromitsmotherrock

（母巖）becauseofthewater,wind,glacier.

?Carrying(搬運(yùn)作用)→theprocessthatrockiscarriedfromoneplacetoantherplace.Becauseof…

?

Sedimentation（沉積作用）

→theprocessinwhichthecarryingmaterialssinktothebottomofgroundwhenthepowerofgravityofthematerialsisbiggerthanthecarryingforce.

?

Rock-formationaction（成巖作用）

→theprocessthatthematerialssunktogroundsurfacetobecomehardorsolidrockbody.

?Crustmovement（地殼運(yùn)動(dòng)）

?B:Magmatism(magmaticactivities)巖漿作用

(magmaticintrusionandvolcaniceruption)

?Earthquake（地震作用）

(2)Inner-dynamicsgeologicalaction(內(nèi)動(dòng)力地質(zhì)作用)(thedynamicssourceisfromearth?Metamorphism（變質(zhì)作用）

Becauseofthehighpressureandortemperature,therockischangedtoanewkindofrock,Thisrockiscalledmetamorphicrock..Everygeologicalphenomenaistheresultofgeologicalaction.Including:Amineral,rock,Landshape(mountain,river,plain..)TectonicsRock

巖石Sincemineralsarethebuildingblocksofrocks,itisimportantthatyoulearntoidentifythemostcommonvarieties.Mineralscanbedistinguishedusingvariousphysicaland/orchemicalcharacteristics,but,sincechemistrycannotbedeterminedreadilyinthefield,thephysicalpropertiesofmineralsareusedtoidentifythem.§2-1:Themainmineralsintherock(造巖礦物)?

Crystalform（晶形）

?

Hardness（硬度）

(relativetoasteelbladeoryoufingernail),

?

colour(真色，假色，它色)

?

Luster（光澤）

?

Streak(條痕)

(thecolourwhenamineralisgroundtoapowder).

?cleavage（解理）Physicalpropertiesofmineralsincludefeaturessuchas：Quartzishard-itcaneasilyscratchasteelknifeblade.Inmanyrocks,quartzgrainsareirregularinshapebecausecrystalfacesarerareandquartzdoesnothaveacleavage(ie,itdoesnotbreakonregularflatfaces).1Quartz(石英):Quartzisaglassylooking,transparentortranslucentmineralwhichvariesincolourfromwhiteandgreytosmoky.Whenthereareindividualcrystalstheyaregenerallyclear,whileinlargermassesquartzlooksmoremilkywhite.油脂光澤Feldsparisalsohardbutcanbescratchedbyquartz.Feldsparinigneousrocks（火成巖）formswelldevelopedcrystalswhichareroughlyrectangularinshape,andtheycleaveorbreakalongflatfaces.Thegrains,incontrasttoquartz,oftenhavestraightedgesandflatrectangularfaces,someofwhichmeetatrightangles.2Feldspar（長石）:Feldsparistheothercommon,light-colouredrock-formingmineral.Insteadofbeingglassylikequartz,itisgenerallydulltoopaque（不透明）withaporcelain-likeappearance.Colourvariesfromred,pink(orthoclase正長石),andwhitetogreen,grey(plagioclase斜長石).Plagioclase斜長石Orthoclase正長石Themostcommonamphiboleishornblende（角閃石）.Hornblendeisquitesimilartoaugite（普通輝石）inthatbotharedarkminerals,howeverhornblendecrystalsaregenerallylonger,thinnerandshinierthanaugiteandthemineralcross-sectionsarediamond-shaped.hornblende（角閃石）3Amphibole（閃石）Themostcommonpyroxenemineralisaugite.Augiteisgenerallydarkgreentoblackincolourandformsshort,stubby（短而粗）crystalswhich,ifyoulookatanend-onsection,havesquareorrectangularcross-sections.Pyroxene（輝石）4Pyroxene輝石Talcoccursingranular（粒狀的）orfoliated（片狀的）massessometimesknownassoapstone（皂石）.Itiswhitetogreen,sometimesgreyorbrownish.Itisverysoftandwillbescratchedbyafingernail.Ithasagreasyfeel（滑感）5Talc（滑石）Olivineinthejewellerytrade,isyellow-green,translucent（半透明的）andglassylooking.Crystalsarenotcommon;itusuallyoccursasroundedgrainsinigneous（火成的）rocksorasgranularmasses.Olivineisalmostashardasquartz;itdoesnothaveawell-developedcleavage.6Olivine橄欖石Micaiseasilydistinguishedbyitscharacteristicofpeelingintomanythinflatsmoothsheetsorflakes（薄片）.Thisissimilartothecleavageinfeldsparexceptthatinthecaseofmicathecleavageplanesareinonlyonedirectionandnorightanglefacejoinsoccur.Micamaybewhiteandpearlyordarkandshiny.7Mica雲(yún)母8Gypsum(plasterstone,石膏)9Kaolinite(高嶺石)10Montmorillonite（蒙脫石）11Watermica（伊利石）§2-2:Rock(巖石)(一種或多種礦物組成的集合體)

一、Theclassificationofrockaccordingtothecauseofformationigneousrock（巖漿巖）

(magmarock)sedimentaryrock（沉積巖）

metamophicrock（變質(zhì)巖）巖石二、Igneousrock1theformationofigneousrock:DeepwithintheEarth,rockiskeptinamolten（融熔的）stateduetoextremetemperatureandpressure.

Thismoltenrockiscalledmagma（巖漿）.

Themagmaisconstantlymovingandsometimesmovesitswaytothesurfacethroughthecracks（裂縫）inthesolidrock.

Onceitreachesthesurface,itiscalledlava（熔巖）.

Thelocationitpushesthroughtothesurfaceiscalledavolcano（火山）.

Theopeninginthevolcanothatthelavaeruptsoutofiscalledavent(出口).

Formanyvolcanos,thereismorethanonevent.

Oftenvolcanoshaveafunnel（漏斗）shapewithapitatthetop.

Thispitiscalledavolcaniccrater（火山口）.

Ifthiscraterbecomesverylarge,thewallsofthecratermightcollapsetoproduceafeaturecalledacaldera（噴火山口）HowIgneousrockrockIsFormedPyroclasticash(火山灰)Batholith巖基Captivemass俘虜體laccolith巖盤巖牆Rockwall巖株Volcanoneck火山頸Lavaflow巖流theformationstateofigneousrock（巖漿巖的產(chǎn)狀）Sill巖床3theclasscificationofigneousrock（巖漿巖的分類）

（1）Accordingtotheformationstate(按產(chǎn)狀)

?IntrusiveIgneousRocks（侵入巖）

-usuallymediumtocoarsegrainedtextureduetoslowcooling.Typicallylightcoloured.

?ExtrusiveIgneousRocks（噴出巖）

-glassyorfine-grainedduetorapidcooling.Mayhavevoidsduetodegassingofthemagma.Typicallydarkcoloured.(2)AccordingtotheSilicaContentandMineralComposition(根據(jù)二氧化矽含量)

?AcidIgneousRocks(酸性巖)-silicarich(>65%byweight)composedmainlyoflightcolouredminerals(eg.feldspars,quartz)

?IntermediateIgneousRocks（中性巖）

silica50-65%byweight,composedmainlyoffeldspars,somemafic（鐵鎂質(zhì)的minerals,withsomequartz.

?BasicIgneousRocks（基性巖）

-silicapoor(<50%byweight)containsignificantamountsofmaficordarkcolouredferromagnesianminerals(eg.olivines,pyroxenes,amphiboles,micas).Nofreequartz.thedescriptionofmainigneousrock

（巖漿巖描述）

?granite（花崗巖）Graniteisanigneousrockthatiscomposedoffourminerals.Thesemineralsarequartz,feldspar,mica,andusuallyhornblende.Graniteformsasmagmacoolsfarundertheearth'ssurface.Becauseithardensdeepunderground，itcoolsveryslowly.Thisallowscrystalsofthefourmineralstogrowlargeenoughtobeeasilyseenbythenakedeye.Graniteisanexcellentmaterialforbuildingbridgesandbuildingsbecauseitcanwithstandthousandsofpoundsofpressure.Itisalsousedformonumentsbecauseitweathersslowly.Engravingsinthegranitecanbereadforhundredsofyears,makingtherockmorevaluable.GraniteisquarriedinmanyplacesintheworldincludingtheUnitedStates.TheStateofNewHampshirehasthenickname"GraniteState"becauseoftheamountofgraniteinthemountainsofthatbeautifulstate.TheCanadianShieldofNorthAmericacontainshugeoutcroppings(surfacerocks)ofgranite.

?

porphyriticgranite(花崗斑巖)

shallowintrusiverock（淺成侵入巖）

moderatecrystallization（中等結(jié)晶）

porphyriticstructure斑狀結(jié)構(gòu)

quartz-feldspar-blackmica花崗斑巖

?rhyolite

（流紋巖）

Rhyoliteisverycloselyrelatedtogranite.Thedifferenceisrhyolitehasmuchfinercrystals.Thesecrystalsaresosmallthattheycannotbeseenbythenakedeye.Rhyoliteisanextrusiveigneousrockhavingcooledmuchmorerapidlythangranite,givingitaglassyappearance.Themineralsthatmakeuprhyolitearequartz,feldspar,mica,andhornblende.Rhyolite流紋巖

?Diorite(閃長巖)1abyssalintrusiverock2wellcrystallization3feldspar,quartz,amphibole?

Dioriteporphyrite（閃長玢巖）1shallowintrusiverock,2mediancrystallization3feldspar,quartzamphiboleDaciteisanextrusiveigneousrock.Theprinciplemineralsthatmakeupdaciteareplagioclase,quartz,pyroxene,orhornblende.Dacite安山巖?Dacite（安山巖）Andesite

?pyroxenire(輝巖)

1abyssalintrusiverock2wellcrystallization3amphibole,phyroxenefeldspar

Basaltsaredarkcolored,fine-grainedextrusiverock.Themineralgrainsaresofinethattheyareimpossibletodistinguishwiththenakedeyeorevenamagnifyingglass（放大鏡）.Theyarethemostwidespreadofalltheigneousrocks.Mostbasaltsarevolcanicinoriginandwereformedbytherapidcoolingandhardeningofthelavaflows.SomebasaltsareintrusivehavingcooledinsidetheEarth'sinterior.?basalt玄武巖1ultrabasicrock（超基性巖石）

(sio2<45%)2abyssalintrusiverock（深成巖）

3wellcrystallization（結(jié)晶好）

4olivine；pgroxene?olivinerock(橄欖巖)?Obsidian黑耀巖Obsidianisaveryshinynaturalvolcanicglass.Whenobsidianbreaksitfractureswithadistinctconchoidal（貝殼狀的）fracture.Noticeinthephototothelefthowitfractures.Obsidianisproducedwhenlavacoolsveryquickly.Thelavacoolssoquicklythatnocrystalscanform.Whenpeoplemakeglasstheymeltsilicarockslikesandandquartzthencoolitrapidlybyplacingitinwater.Obsidianisproducedinnatureinasimilarway.Obsidianisusuallyblackoraverydarkgreen,butitcanalsobefoundinanalmostclearform.Pumiceisaverylightcolored,frothy（起泡的）volcanicrock.Pumiceisformedfromlavathatisfullofgas.Thelavaisejectedandshotthroughtheairduringaneruption.Asthelavahurtles（急飛）throughtheairitcoolsandthegasesescapeleavingtherockfullofholes.?Pumice（浮石）Pumiceissolightthatitactuallyfloatsonwater.Hugepumiceblockshavebeenseenfloatingontheoceanafterlargeeruptions.Somelavablocksarelargeenoughtocarrysmallanimals.三、sedimentaryrock（沉積巖）1theformationofsedimentaryrock:Forthousands,evenmillionsofyears,littlepiecesofourearthhavebeeneroded--brokendownandwornawaybywindandwater.Theselittlebitsofoureartharewasheddownstreamwheretheysettletothebottomoftherivers,lakes,andoceans.Layerafterlayeroferodedearthisdepositedontopofeach.Theselayersarepresseddownmoreandmorethroughtime,untilthebottomlayersslowlyturnintorock.HowSedimentaryRockIsFormedSedimentsaresubdividedintothreetypes:

?1

Clasticordetritalsediments（碎屑巖）

Comprisingparticlesofvarioussizescarriedinsuspensionbywind,waterorice.Sand(砂巖)isanexampleofaclasticsediment.Silt（粉砂巖）andsandsizeparticlesarecarriedinsuspensionbywind,waterandice.

2theclassificationofsedimentaryrock:

?2

Chemicalorprecipitatedsediments（化學(xué)巖）

whicharecarriedinaqueoussolution.Salt(halite)isanexampleofachemicalprecipitate.·

?3

Organicorbiogenicsediments（有機(jī)巖）

precipitatedoraccumulatedbybiologicalagents.Manyorganismspromotetheprecipitationofcalcitetoformbiogenicallyprecipitatedcalcareous（含鈣的）muds.3Thetextureandstructureofsedimentaryrock

沉積巖的結(jié)構(gòu)和構(gòu)造沉積巖的層理構(gòu)造平行層理斜層理波狀層理印模粒序?qū)永斫徊鎸永沓练e巖的結(jié)構(gòu)特徵砂?？紫赌z結(jié)物砂粒粘粒粉粒鐵餅形的Sphericity球形度[sfe’risiti]4thedescriptionofsedimentaryrockConglomeraterocksaresedimentaryrocks.Theyaremadeupoflargesedimentslikesandandpebbles（鵝卵石）.Thesedimentissolargethatpressurealonecannotholdtherocktogether;itisalsocementedtogetherwithdissolvedminerals.?

gravelstone(conglomerate)礫巖(clasticrock)?

sandstone(d=2-0.05mm)砂巖Sandstonerocksaresedimentaryrocksmadefromsmallgrainsofthemineralsquartzandfeldspar.Theyoftenforminlayersasseeninthispicture.Theyareoftenusedasbuildingstones.?

siltstone(d=0.05-0.005mm)粉砂巖?

mudstone(d<0.005mm)泥巖kaolinite(高嶺石)montorillonite（蒙脫石）

watermica（伊利石）MineralCompositionShalerockisatypeofsedimentaryrockformedfromclaythatiscompactedtogetherbypressure.Theyareusedtomakebricks?

shalestone(d<0.005mm)葉巖Limestonerocksaresedimentaryrocksthataremadefromthemineralcalcitewhichcamefromthebedsofevaporatedseasandlakesandfromseaanimalshells.Thisrockisusedinconcreteandisanexcellentbuildingstoneforhumidregions.colorgrey?

limestone石灰?guī)r?

dolomiterock白雲(yún)巖color:white-greymineral:dolomit?

Gypsum石膏Gypsumrocksaresedimentaryrocksmadeupofsulfatemineralandformedastheresultofevaporatingseawaterinmassiveprehistoricbasins.ItisverysoftandisusedtomakePlasterofParis,casts,molds,andwallboards.四、Metamorphicrock（變質(zhì)巖）Metamorphicrocksaregeneratedbyrecrystallizationofeitherigneousorsedimentaryrocksbytheactionofanyorallofthefollowing:Pressure,Temperature,PoreFluids.

Thetypeofmetamorphicrockisdeterminedbytheparentrock（母巖）andtheP/Tconditions.Ingeneral,metamorphismcauses:GrowthofnewmineralsDeformationandrotationofmineralgrainsRecrystallizationofmineralsaslargergrains1theformationandclassificationofMetamorphicrocks變質(zhì)巖的形成接觸變質(zhì)巖的形成區(qū)域變質(zhì)巖的形成2thedescriptionofMetamorphicrocks

?

Marble

（大理巖）Marbleismetamorphosedlimestoneordolomite.Bothlimestoneanddolomitehavealargeconcentrationofcalciumcarbonate(CaCO3).Marblehasmanydifferentsizesofcrystals.

Marblehasmanycolorvariancesduetotheimpurities(雜質(zhì))presentatformation.Someofthedifferentcolorsofmarblearewhite,red,black,mottledandbanded,gray,pink,andgreen.Marbleismuchharderthanitsparentrock.Thisallowsittotakeapolishwhichmakesitagoodmaterialforuseasabuildingmaterial,makingsinktops,bathtubs,andacarvingstoneforartists.Today,headstonesaremadefrommarbleandgranitebecausebothoftheserocksweatherveryslowlyandcarvewellwithsharpedges.?

Quartzite（石英巖）Quartziteiscomposedofsandstonethathasbeenmetamorphosed.Quartziteismuchharderthantheparentrock,sandstone.Itformsfromsandstonethathascomeintocontactwithdeeplyburiedmagmas.Quartzitelookssimilartoitsparentrock.Thebestwaytotellquartzitefromsandstoneistobreaktherocks.Sandstonewillshatterintomanyindividualgrainsofsandwhilequartzitewillbreakacrossthegrains.

Geological

Structure

地質(zhì)構(gòu)造§2-1geologicaltimeandChronologicalscale

地質(zhì)年代與地質(zhì)年代表

一、GeologicalTime

Geologicaltimeisamethodoforderingandmeasuringpastevents.Theorderingofeventsusesagroupofobservationalmethodsknownas:

1Absolutedatingmethods(絕對年代法)

2Relativedatingmethods（相對年代法）1AbsolutedatingmethodsAbsolutedatingmethodsarethosethatgenerateanageinyears.Therearetwoprincipalmethods:oneisthemethodwhichrelyoneventinthegeologicalrecordwithverystrongannualcyclicity(週期性),suchastreegrowthrings,coralgrowthcyclesvarves（紋層）

(annualclaysedimentlayers).AnotherMethodsismorecommonlyusednowdayswhichrelyonthedecayofnaturallyoccurringradiogenicisotopes:

Radiometricdatingisnotwithoutdifficultiesbutisbyfarthemostwidespreadmethodappliedtodetermineabsoluteagesbetween100and4500My.Uranium(鈾),Thorium（釷）

andPotassium（鉀）arebyfarthemostcommonradiogenicisotopesintheEarth'scrust.Radiocarbonisimportantindatingorganicremainsfromtherelativelyrecentpast.2relativedatingmethodsRelativedatingmethodsusegeologicalprinciplestoplaceeventsinchronologicalorder.whichinclude:

?stratasuperpositionmethod（地層層序法）?fossilsuccessionmethod（化石演變法）?themethodofrocklayerscontactrelation

（巖層接觸關(guān)係法）.

?Theprincipleofsuperpositionstatesthatolderbedsarecoveredbyyoungerbeds.Inotherword,theyoungestunitisusuallyatthetopinasedimentarysequence.TheyoungestlayerTheoldestlayer

?Theprincipleoffossilsuccessionstatesthatorganismsevolvethroughtimesothatparticularformscanbeusedasagemarkerswherevertheyarefound.

?

Themethodofrocklayerscontactrelationstatesthatthecontactrelationsamongrocklayersisthehistoryrecordsofcrustmovement,magmaactivities.Sogeologicaleventscanbeorderedbytherelationofrocklayers,theseincludes：①therelationsamongsedimentaryrock,

（沉積巖之間的接觸關(guān)係）②therelationsamongtheigneousrock,（巖漿巖之間的接觸關(guān)係）③therelationbetweensedimentaryrockandigneousrock.（沉積巖和巖漿巖之間的接觸關(guān)係）①TherelationsamongsedimentaryrockTherelationsamongsedimentaryrockcanbedividedinto：

conformity（整合）

Unconformity（不整合）.Theconformitymeansthatstratawasformedinastablesedimentaryenvironment,thedipandstrikeofstrataarebasicallythesame.conformity（整合接觸關(guān)係）Unconformity（不整合）.Theunconformitymeanthereisabreakinsedimentation,aperiodoferosionoranepisodeofdeformation,Unconformitiesrangefromminorerosionalbreakstostrongangulardiscordancesinbedding.Anunconformityindicatesaperiodwherenorockrecordisaccumulated.Theyaretime-breaksofindeterminatelength.整合接觸平行不整合接觸角度不整合接觸②therelationsamongtheigneousrock,巖漿巖之間的接觸關(guān)係Cross-cuttingrelationshipsamongigneousrocksindicatethatintrusionrocksmustbeyoungerthantherockstheycut.③therelationbetweensedimentaryrockandigneousrock.Cross-cuttingrelationshipsbetweenigneousrocksandsedimentaryrockIndicatethatsedimentaryrockincludedpebblesandfragmentsmustbeolderthanthehostrockcontainingthem.二、ChronologicalscaleThegeologictimescalewasoriginallyasetofrelativedatesbutthevariouseons（宙）,eras（代）,periods（紀(jì)）andepochs（世）havenowbeenaccuratelydatedwiththeaidofradiometricmethods.Theimportantdatesare:4,600My-theageoftheEarthandSolarSystem3,600My-theearliestlife570My-thefirstappearanceofabundantandvariedorganicforms200My-thebreak-upofthesupercontinent66My-thedisappearanceofthedinosaurs多麼富有想象力的比喻！§2-2Basicshapeandclassificationofgeologicalstructure

地質(zhì)構(gòu)造的基本形態(tài)和分類一、intruductionGeologicalstructureisthestudyofthepermanentdeformationandrockfailurecreatedbythechangesinstressthroughgeologictime.Itisbyfarthemostimportantaspectofgeologyfortheengineertounderstand.Tectonic構(gòu)造processesareresponsibleforthemanydiscontinuityplanes（不連續(xù)面）(fractures裂隙,faults斷層,joints節(jié)理)thatpermeaterockmassescontrollingtheirstrength,stress-straincharacteristicsandthetransmissionandstorageoffluids.Structuresmaybeconvenientlysubdividedintotwogroups:brittlestructures脆性構(gòu)造

recordingthebrittle-elasticfailure彈脆性破壞

ofrocksinthepast.Faultsandjointsfallinthisbroadcategory.ductilestructures柔性構(gòu)造

preservingthepermanentviscoplastic（粘塑性）

deformationofrockthroughoutgeologictime.Foldsandmetamorphicfoliationsaretheexpressionofthistypeofstructure.Themoststrikingfeaturesofrocksasengineeringmaterialsisthattheyarenotsimple,isotropic各向同性的,elastica