2024国际地球科学奥林匹克竞赛试题

IESO2024WRITTENTESTPART1

Testtime:8:00–12:00

Scores:TheanswersheetautomaticallysavedattheendofWrittenTestPartIwillbetheonlybasisforscoring.Allquestionsshouldhavemorethanonecorrectanswer,unlessitislabeled“onlyonecorrectanswer”.Whenchoosingonecorrectanswer,youwillreceive1point;whilechoosingawronganswer,youwilllose0.5point.Thescoreofeachquestionwillnotbelowerthan0.

Question1:

TheimageFigureQ1.1(a)isaninternalmoldgastropodfossil,showingtheinternalmorphologytypicalofgastropods(refertotheimageofamoderngastropodinFigureQ1.1(b)).Whatcanwelearnfromtheinternalmold?(onlyonecorrectanswer)

(a)(b)

FigureQ1.1

a)Formoftheoutersurfaceoftheshell

b)Formoftheinnersurfaceoftheshell

c)Thechemicalcompositionoftheshell

d)Thegutstructureofthisorganism

e)Detailsofmuscletissueofthisorganism

Question2:

Antitropicaldistributionisatypeofdisjunctdistributionwhereaspeciesorcladeexistsatcomparablelatitudesacrosstheequatorbutnotwithinthetropics.Thedistributionofthespecies/cladescanbebothpolarandtemperatezones.Manymodernandfossilmarineanimalgroupsexhibitantitropicaldistribution,includingmollusks,echinoderms,fishes,insects,andothers.WhatcouldNOTbethereasonforanantitropicaldistribution?(onlyonecorrectanswer)

a)Animalscanmigratethrough“stepping-stone”islandsscatteredacrossthetropicalseafromonesidetotheother

b)Species/cladesfrombothsidesmayhaveoriginatedfromdifferentancestors.

c)Animallarvaecanmigrate,oftenpassively,fromonesidetotheother

d)Thesespecies/cladeswereinitiallytogether,buttectonicmovementsmightseparatethemintotwodistinctsides

ClimateChange(Questions3-8)

Introduction:

TheCarbonCycleplaysavitalroleinclimatechange.Accurateassessmentofanthropogeniccarbondioxide(CO2)emissionsanditsredistributionamongtheatmosphere,ocean,andterrestrialbiosphereiscriticaltounderstandingtheglobalcarboncycleandpredictingfutureclimatechange.

TheKeelingCurve,namedafterscientistCharlesDavidKeeling,illustratestheriseofatmosphericCO2levelsinthepast.Establishedinlate1950satMaunaLoaObservatoryinHawaii,Keeling’smeasurementsrevealedasteadyincreaseinCO2duetohumanactivitieslikefossilfuelburning.Thecurve’supwardtrendservesasastarkindicatorofanthropogenicdriverforclimatechange,urgingglobalactiontoreduceCO2emissionsandmitigateitsclimaticeffects.Today,theKeelingCurveremainsacriticaltoolinclimatescience,emphasizingtheneedforsustainablesolutionstoaddress

climatechange.

FigureQ3.1CharlesDavidKeelingandtheKeelingCurve

FigureQ3.2PositionoftheMaunaLoaObservatoryinHawaii

FigureQ3.3TheKeelingCurve,from2020to2024

Question3:

FigureQ3.3

showsazoomed-inversionoftheKeelingCurve.Theredlineandsymbolsrepresentthemonthlymeanvalues,centeredonthemiddleofeachmonth.Theblacklineandsymbolsrepresentthesame,afterremovingtheaverageseasonalcycle.WhatisthemostimportantdriverforthefluctuationofCO2levelwithinayear?(onlyonecorrectanswer)

a)Atmosphericcirculation

b)Vegetationchanges

c)ElNiño-SouthernOscillation(ENSO)

d)Humanactivity

Question4:

FossilfuelCO2emissiongenerallyaccountsfor88%ofanthropogenicCO2emissions.ThemeanannualfossilfuelCO2emissionfrom2013-2022was35.3GtCO2/year.47%oftheanthropogenicCO2emissionsremainintheatmosphere,andtheoceancanabsorb

10.4GtCO2peryear.HowmuchCO2shouldtheterrestrialecosystemtakeuptoensuretheglobalCO2balance?(onlyonecorrectanswer)

a)4.2GtCO2/year

b)6.1GtCO2/year

c)8.5GtCO2/year

d)10.9GtCO2/year

Question5:

FigureQ5.1showstheCO2growthrate(CGR),whileFigureQ5.2illustratestheanomaliesofCGRandtheglobalcarbonfluxes.Carbonfluxesfromdifferentsourcesareaffectedbyvariousfactors,andthereforehavedifferentspatiotemporalcharacteristics,forexample,duetotheinfluenceofENSO,oceannetcarbonfluxtendstohaveacycleof5-20years.ThedifferentcolorsinFigureQ5.2standforcarbonfluxesfromdifferentsourcesincludinglandnetflux,oceannetflux,fossilfuelemissions,andlandusechangeemissions.Whichcolorrepresentstheoceannetflux?(onlyonecorrectanswer)

FigureQ5.1TheannualglobalincreasesofCO2

1

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FigureQ5.2TheanomaliesofCGRandglobalcarbonfluxes

a)①

b)②

c)③

Question6:

FigureQ6.1showstherelationshipsbetweenthecumulativeamountofCO2emissionsandtheriseofglobaltemperature.Itisestimatedthat2590GtCO2hasbeenemittedbyhumanbeingssince1850.Inordertolimitthetemperatureincreaseto1.5℃(comparedwith1850),whatisthemaximumamountthatcouldbeemittedbeforewereachthislimit?(onlyonecorrectanswer)

FigureQ6.1Cumulativecarbonemissionsandrisingglobaltemperature

a)200Gt

b)600Gt

c)1000Gt

d)1500Gt

e)2000Gt

Question7:

Whichis(are)theprimaryform(s)ofglobaloceancarbonsink?

a)Methaneemission

b)Carbonateprecipitation

c)Organicmatterburial

d)Coaldeposition

e)Methaneclathrateformationinmarinesediment

f)Methaneclathrateformationinpermafrost

Question8:

FigureQ8.1showsthecontributionsofdifferentgeographicalfactorsthatmayaffecttheglobaltemperature,whichofthefollowingstatementsistrue?(onlyonecorrectanswer)

FigureQ8.1

a)Thenegativeeffectofaerosolscomesfromtheirinteractionswithcloudsandradiation

b)Thenegativeeffectofalbedocomesfromtheincreaseofvegetationoncontinents

c)Thenegativeeffectofalbedocomesfromthedecreaseofsolarradiation

d)ThepositiveeffectofozonecomesfromtheincreaseofO2concentrationinthetroposphere

TheHistoryoftheEastAsianMonsoon(Questions9-15)

Introduction:

FigureQ9.1

TheAsiansummermonsoonisthestrongestmonsoonsystemonEarth,straddling

~10°-55°Nfromtropicaltowarmtemperateregions,bringingabundantprecipitationoncontinents.However,thesummermonsoonwasnotalwaysthisstrong.For

example,EastAsiawasdrymorethan~26millionyearsago(Ma),whilethesummermonsoonsystemexpandednorthwardlywiththenorthwardmovementoftheIndianplateandupliftoftheTibetanPlateau(TP).

FigureQ9.2

Meansurfacetemperature(℃;shading)averagedbetween1979and2010,basedontheERA-Interimdataset.Elevationisindicatedbycontourlines,withtheplateau

boundary(3000m)markedbyathicksolidline.

Question9:

Inthelow-tomid-latituderegions,theatmospherictemperaturegenerallydecreaseswithaltitude,i.e.alapserateof~6.5°C/km.MostoftheTibetanPlateauhasan

averagesurfaceelevationof4000m.Accordingly,thesurfacetemperatureacrosstheTibetanPlateauwouldbemorethan26°Clowerthanatsealevelatthesamelatitude.However,thesummersurfacetemperatureofTibetanPlateauisonly~10°Clower.

ThismakesthesurfaceairintheTibetanPlateaumuchwarmerthanthesurrounding(i.e.,regionsoutsideofTibetanPlateau)airofthesamealtitude.Whatisthereason?(onlyonecorrectanswer)

a)TheTibetanPlateauistectonicallyactive,soithasahighgeothermalheatflux,whichheatsupthesurfaceaswellasthesurfaceair

b)TheTibetanPlateauistoohightoobeythelapserateruledescribedabove(i.e.,temperaturedecreasesatarateof~6.5°C/km)

c)ThesurfacetemperatureoftheTibetanPlateauiscontrolledbylocalradiationeffects

d)ThesurfaceoftheTibetanPlateauisheatedbyintensecosmicraysbecauseitisclosertothesun

Question10：

ThroughwhichofthefollowingprocessesdoestheTibetanPlateauinfluencetheAsianmonsoon?(onlyonecorrectanswer)

a)Blockingcolddryairfromthenorthwest

b)Formingtropicalclimate

c)ForcingthewesterlywindstoflowaroundthenorthernrimoftheTibetanPlateautoformalow-pressureridge

d)ThesurfaceofTibetanPlateauremainscoldinallseasons

Question11：

HereisaschematicdiagramshowingtheimpactoftheTibetanPlateauheatingon

atmosphericcirculation(FigureQ11.1).Redcontoursindicatethegeopotentialheightanomalyisolineson200-hPaandbluecontoursdenotechangesinsealevelpressure.ContoursshowtheanomaliescausedbyTibetanPlateauheatingwithsolidand

dashedcurvesindicatingpositiveandnegativeanomalies,respectively.

FigureQ11.1

Choosethecorrectlabel(s)forAnticyclonicanomalies(orhigherpressureinthemiddle,labeledas"A")andCyclonic(orlowerpressureinthemiddle,labeledas"C")anomaliesonthegraph.

a)Anticyclonicanomalies

b)Cyclonicanomalies

c)Anticyclonicanomalies

d)Cyclonicanomalies

e)Cyclonicanomalies

Question12:

StudieshaveshownthatduringtheCenozoic,largepartsofSouthChinawerearid.WhichofthefollowingdescriptionsoftheupliftoftheTibetanPlateau,theAsianmonsoonandaridityiscorrect?(onlyonecorrectanswer)

a)SouthChinawasdrybecauseitwasfurtherfromoceansthatitisnow

b)UpliftofTibetanPlateauwouldonlyenhancetheariditybyinhibitingmoistureflow

c)UpliftoftheTibetanPlateauhasnoeffectonthearidity

d)TheairpressuregradientcreatedbytheupliftoftheTibetanPlateauleadstotheenhancementoftheEastAsianMonsoon

Question13:

SomechemicalcompoundsattheEarth’ssurfacemaybetransportedtothe

stratosphereviatheAsianSummerMonsoon.Inthiscase,whichofthefollowingstatementsis(are)correct?

a)Molecularoxygenproducedbyoxygenicphotosynthesismaybetransportedtothestratosphere,whichultimatelyincreasestratosphericozonelevelsandprotectsourplanet

b)Sulfateaerosolsfromairpollutionmaybetransportedtothestratosphere,whichcouldcoolourplanetbyreducingincomingsolarradiation

c)Chlorinefromseawaterorairpollutionmaybetransportedtothestratosphere,whichultimatelydestroysthestratosphericozonelayer

d)Watervapormaybetransportedtothestratosphere,whereitisphotolyzedintoH2andO2,leadingtosignificantincreasesinatmosphericO2

Question14:

ReconstructingtheuplifthistoryoftheTibetanPlateauiscrucialforunderstanding

theevolutionoftheAsianSummerMonsoon.Geochemistsusuallyusegeochemicalproxiestoachievethisgoal.WhichofthefollowingstatementsisNOTareasonableapproachforreconstructingtheuplifthistoryoftheTibetanPlateau?(onlyonecorrectanswer)

a)ReconstructingthechangeoftemperatureovertheTibetanPlateau

b)ReconstructingthechangeinCFC-11(chlorofluorocarbon11)gases

c)ReconstructingthechangeofprecipitationovertheTibetanPlateau

d)ReconstructingthechangeofecosystemovertheTibetanPlateau

Question15:

WhatistheimplicationofastrongAsiansummermonsoonfortheregionsitaffects?(onlyonecorrectanswer)

a)IncreasedriskofdroughtsinEastAsia

b)Increasedrainfallfavoringhigherprimaryproductivityacrosscontinents

c)Adecreaseinthefrequencyoftropicalstorms

d)Higheraveragetemperaturesduetoincreasedevaporationandhumidity

TheEarthSystemduringaSnowballEarthEvent(Questions16-22)

Introduction:

FigureQ16.1(A)AschematicillustrationofsnowballEarth;(B)Pre-industrialEarth;(C)SeaiceextentduringasnowballEarthevent.CO2denotestheatmosphericCO2concentration,S0isthesolarconstant,andαisplanetaryalbedo(i.e.,reflectivity).

MultiplelinesofgeologicalevidenceindicatethattheEarthlikelyenteredaglobalglaciation(alsocalledSnowballEarthstate;seeFig.Q16.1(A))twiceduringtheLate

Neoproterozoic(720–541millionyearsago).Ineachevent,theglaciationlastedforatleastafewmillionyears,withtheannualmeansurfacetemperatureaslowas-40°Cneartheequator,and-100°Cnearthepoles.Correspondingly,theatmospherewasdryandthemaximumprecipitationratewas~20cm/year.Bycomparison,thepresentannualmeansurfacetemperatureneartheequatoris~28°Candthemaximumprecipitationrateneartheequatoris~400cm/yearinpresentday.

Question16:

Whatwerethepotentialcause(s)forEarthtoenteraglobalglaciationduringtheLateNeoproterozoic?

a)Landwasnotexposedabovesealevel,i.e.,nocontinentsabovesealevel.

b)Solarluminosityincreasedwithtime.Thatis,theSunwasnotasbrightasinthepresentday.

c)Theconcentrationofatmosphericgreenhousegaseswasverylow.

d)Theoceanwasshallowerandsmaller.

e)TheEarthwasrotatingtoofast.

Question17:

Hint:thethermalconductivityoficeisapproximately2.5W/(m.K)(slightlydependentontemperature,butnotimportanthere).EstimatetherateofheatlossatthebottomoftheseaiceduringaSnowballEarthevent.

DuringaSnowballEarthevent,seaicewasaround1000mthick,beneathwhichtherewasadeepliquidocean.Whywasn'tthewholeoceanfrozen?

a)Theheatcapacityoftheoceanwassufficientenoughtopreventitfromfreezingcompletelyatthewatericeinterface(i.e.,withoutliquidwater)

b)Thelatentheatoffreezingofseawaterissufficientlyhightowarmtheunderlyingseawaterasiceformsatthesurface

c)Thegeothermalheatflux,whichhadavalueofapproximately0.1W/m2,wascontinuouslyheatingtheocean

d)Thedecayofradioactiveelementsintheoceanwasconstantlyheatingtheocean

e)MeteoritescontinuouslyhittheEarth,preventingpermanentcompletefreezingoftheocean

Question18:

Whatarethepotentialmajorprocess(es)thatledtotheendoftheNeoproterozoicSnowballEarthevent?

a)Volcanicoutgassing

b)Reducedweatheringofrocks

c)Morecloudsintheatmosphere

d)HumanactivitiesincreasingatmosphericCO2

e)Earthquakesbreakingtheicesheets

Question19:

Whichofthefollowingstatementsis(are)correct?

a)ModernEarthwillenteraglobalglaciationiftheatmosphericCO2concentrationdropsbelowto100ppm,soweshouldencouragegreenhousegasemissiontopreventsuchaneventfromoccurring.

b)ThegreenhouseeffectofatmosphericCO2increasesduringaSnowballEartheventbecausethesurfacetemperatureislow;coldbodiesabsorbheatmoreeasily.

c)ThegreenhouseeffectofatmosphericCO2decreasesduringaSnowballEartheventbecausethesurfacetemperatureislow;thereislittleoutgoinglongwaveradiationfortheatmosphericCO2toblock.

d)ThegreenhouseeffectofatmosphericCO2decreasesduringaSnowballEartheventbecausethesurfacetemperatureislow;theatmosphericwatervapor,which

isapowerfulgreenhousegas,increasesslowlywithsurfacetemperaturewhenthesurfacetemperatureislow.

Question20:

Hydrogenperoxide(H2O2)playsacrucialroleinshapingtheplanetarysurfaceredoxstate.ThereisahypothesisthatH2O2intheanoxicatmospherecouldhavedriventheevolutionofoxygen-mediatingand-usingenzymespavingthewayfortheemergenceandevolutionofoxygenicphotosynthesis.TheatmosphericO2leveloftheLateNeoproterozoicisbelievedtobe1-10%ofpresentatmospherelevel.ItisknownthatH2O2maybeproducedintheatmosphereviathefollowingphotochemicallyinducedreactions:(hv:solarradiation)

O2+hv→O+O(1D)(mainly<242nm)

O3+hv→O2+O(1D)(mainly<320nm)

H2O+hv→OH+H(mainly<190nm)

NO2+hv→NO+O(3P)(visiblelight)

O(3P)+O2+M→O3

H2O+O(1D)→2OH

OH+CO→CO2+H

H+O2+M→HO2+M

2OH+M→H2O2+M

2HO2→H2O2+O2

ItisknownthatH2O2canbeproducedintheatmosphereviaphotochemicalreactions.ThefreezingpointofH2O2is-1°C.DuringaSnowballEarthevent,whichstatementsiscorrect?(onlyonecorrectanswer)

a)ProductionofatmosphericH2O2wasimpossiblebecausetherewasnowatervaporduringaSnowballEarthevent

b)TheproductionrateofatmosphericH2O2wasextremelyslowbecauseonlylimitedsunlightreachedEarth’ssurface

c)H2O2intheatmosphereincreasedwithtimebecausewithlimitedwaterdeposition

(i.e.,precipitation)atmosphericH2O2cannotbedepositedonEarth’ssurface

d)H2O2accumulatedintheicebecauseitsfreezingpointisonlyslightlylowerthanwater

Question21:

WhatwouldyouexpectattheendoftheNeoproterozoicSnowballEarthevents?

a)Ahighgreenhousegasconcentrationintheatmosphere

b)ChemicaldecompositionofH2O2storedinthethickicecouldactasasourceofO2tobereleasedintotheatmosphere

c)AsignificantincreaseinatmosphericO2levelsduetochemicaldecompositionofmeltwater

d)Themeltwaterwouldcauseadramaticoverturningoftheocean

Question22:

WhichofthefollowingfeedbackmechanismswouldbeexpectedduringaSnowballEarthevent?(onlyonecorrectanswer)

a)Icereflectsmoresunlight(positiveice-albedofeedback)

b)Plantsonlanddied,resultinginlessCO2absorptionandburial(negativeCO2feedback)

c)OceansstoredlessCO2duetoincreasedsea-icecoverage(negativeCO2feedback)

d)Theatmospheretransportedmoreheatfromtheequatortothepoles(negativeheattransportfeedback)

TheDepositionalSystem(Question23-30)

Introduction:

Acompletesedimentaryprocessincludes:weatheringanderosionoftheparentrock,transportationofsediment,andsedimentdeposition.Amongthese,sedimenttransportationismainlyviarivers;sedimentdepositionmainlyoccursindeltasorshallowmarineenvironments.Deltadepositioniscloselyrelatedtocarbonburialandtheformationofoilandgasreservoirs.similarlycarbonatesedimentation,normallyoccurringinshallowmarineenvironments,isalsoimportantforthecarboncycleandpetroleumformation.

Question23:

Siliciclasticstratadepositedaftertheevolutionoflandplantscontainaproportionofmudrock,thatis,onaverage,20timesgreaterthanequivalentstratafromthepreceding90%ofEarth’shistory.

Twonon-exclusiveexplanationshavebeenproposedtoaccountforthisdifference,whichinvokethepossibleinfluencesofextantplantlifeonmuddysediment:(1)plantsincreasedtotalmudproductiononcontinentsduetoenhancedsilicateweathering;and(2)plantspromotedtheretentionofmudonthecontinents,preventingitfrombeingwashedintothemarineenvironmentviabelow-groundstabilizationofsediment,above-groundbafflesthatreducethevelocityoffluidsandsediment,andthereleaseoforganicby-productsthatpromoteflocculationandsubsequentdeposition.

Recentresearchfocusedonthemudrockcontentofalluvialandtidallandscapesthatremainedlocallyunvegetatedevenafterthegreeningofthecontinents,namelyinclinedheterolithicstratification(IHS)thatrecordssubmergedin-channelbars.Theprimaryresultisasfollows:

FigureQ23.1:Examplesofinclinedheterolithicstratification(IHS)(Basedonthemudcontent)

FigureQ23.2:PercentageoftotalnumberofIHSreportedfromthePaleoproterozoictoCarboniferous.

WhichofthefollowingstatementsisNOTcorrect?(onlyonecorrectanswer)

a)TheorderoftheIHSmudcontentis:Class1<Class2<Class3<Class4

b)Thealluvialandtidallandscapesinthisstudyareawayfrombiomechanicalbindingandthebaffleeffectofplants

c)PrecambrianandCambrianIHSaremostlycomposedofsandstone,whereasSiluriantoCarboniferousshowasteadyincreaseintotalmudrockcontent

d)Paleozoiclandplantevolutiontriggeredaglobalincreaseintheproductionandsupplyoffine-grainedsediment

Question24:

Afterlandplantscolonizedcontinents,frequentoccurrencesofwildfiremighthavehadsomeimpactontheEarthsystem.FigureQ24.1showstheHolocenewildfirehistoryintheChangjiangRiverdrainageBasin,whileFigureQ24.2showstheagriculturallanduseandricefielddistribution.

FigureQ24.1:(A)Millennial-scaleclimatefluctuations.(B)Z-scoresoftheBCcurvearecorrectedbythesmoothedgeneralizedadditivemodel.(C)SedimentZnconcentrationinLiangziLake,andGramineaepollencontentfromCoreCM97.(D)Populationchange(blackline)andnumberofhumanculturalsites(Brownbars).

FigureQ24.2:MapofagriculturallanduseandricefielddistributionintheChangjiangRiverdrainageBasin.(A-B)Coverofcropland;(C)Tillagericespreadhistory;(D)Comparisonoffrequency-dependentmagneticsusceptibility(χFD%,i.e.,moremagneticFeminerals)intheChangjiangDeltasedimentsofsubaqueousandLiangzilakecopper(Cu)contentwitharborealpollen(AP)intheChangjiangRiverBasin.

WhichofthefollowingstatementsisNOTcorrect?(onlyonecorrectanswer)

a)Humanactivitieshaveexpanded,leadingtoincreasedimpactsonnature.

b)Humanactivitiescausedincreasedsoilerosion.

c)Theimpactsofhumanactivitiesincreasedsince2000BC.

d)Humanmigratedfromwesttoeast(correspondingtolefttorightinFigureQ24.2)

Question25:

Deltasareprimarilyformedwhenriverscarryinglargeamountsofsedimentdepositthemrapidlyuponmeetingtheocean;meanwhile,seawaterredistributesthesediments,modifingordestroyingofthedelta.Therefore,varioustypesofdeltascanbeproducedthroughinteractionsbetweenriversystemsandtheocean.Deltascanbeclassifiedintothreetypes,i.e.,river-dominateddeltas,wave-dominateddeltas,andtide-dominated

deltas.

FigureQ25.1:Theclassificationofdelta.

FigureQ25.2displaysthetopographyofmoderndelta.Whichofthefollowing

statementsis(are)correct?

FigureQ25.2:Topographyofrepresentativedeltas.

a)DeltaAispredominantlyaconstructivedelta.

b)DeltaAispredominantlyadestructivedelta.

c)DeltaBispredominantlyaconstructivedelta.

d)DeltaBispredominantlyadestructivedelta.

Question26:

58±17Mt/yroforganicmatterfromthecontinentsisburiedinmarinesedimenteachyear,representingthesecondlargestsinkofatmosphericCO2aftersilicateweathering.Thus,itissuggestedthatterrestrialorganicmatterburialwouldregulateclimateovergeologictimescales(≥105yr).Deltasandassociatedshelfdepositsholdbetween70%and90%oftheglobalorganiccarbonburialbudgetinmarinesediments.FigureQ26.1

showsorganiccarbon(OC)contentandcompositioninthestudieddelta.

FigureQ26.1:a)Schematicrepresentationofthestudieddelta.b)Meantotalorganiccarbon(TOC)contentforthetopset,foresetandbottomsetsegments.DotsrepresentthemeasuredTOConeachsample.Verticalbarsrepresentthestandarddeviationforeachsegment,n,numberofsamplesusedtocalculatethemeanTOCforeachsegment,c)Comparisonbetweenarea-normalizedorganiccarbonburialrate.

WhichofthefollowingstatementsisNOTcorrect?(onlyonecorrectanswer)

a)ThemaximumburialofOCperunitoccursatthebaseofthedelta.

b)ThemaximumburialofOCperunitoccursatthetopofthedelta.

c)FinerrockparticlesaremorefavorableforOCburial.

d)TheAmazondeltahasthehighestglobalOCburialraterecordduringtheHolocene.

Question27:

Presentdayhumanactivitiesaremodifyingdeltadynamic,includingtheirabilitytomigratetowardtheocean(prograde),whichcanalterthefluxofcarbonburial.FigureQ27.1displaystheremotesensingimagesofsomemoderndeltas.

FigureQ27.1:Remotesensingimagesofdeltas.a)Mekong,Vietnam,andb)Irrawaddy,Myanmar.Thefloodedareasaremarkedindarkredcolor.c)ThePearlDelta,China.Areasbelowsealevelareinpurplecolor.ThePearlisprotectedfromstormsurgesbycoastalandchannelbarriersasseeninassociatedDigitalGlobeimages.

Whichofthefollowingstatementsis(are)correct?

a)TheMekongRiverDeltaispronetofloodinginhighregions

b)TheIrrawaddyRiverDeltaispronetofloodingincoastalareas

c)MostpartsofthePearlRiverDeltaarebelowsealevelbecauseofsealevelriseduetofossilfuelburning

d)Constructingfarmlandondeltasisconducivetotheirexpansion

e)Constructingfarmlandondeltashinderstheirexpansion

Question28:

AstudyanalyzeddepositsintheQaidamBasin,northwesternChina,anddiscoveredmicrobialcarbonate(microbialites).

FigureQ28.1:Couplingofglobalclimatefluctuationsandtectonicallyinducedlakemigrationhistorywiththetrendsofoxygen,carbon,andstrontiumisotopesandtherelativewaterdepthoftheXichagousection.Globaltemperaturevariationsareshownontheleft.

WhichofthefollowingstatementsisNOTcorrect?(onlyonecorrectanswer)

a)ThelowermicrobialcarbonatemainlyformedintheLateEocene

b)Thelowermicrobialcarbonateformedasthelakelevelrose,whiletheuppermicrobialcarbonaterocksformedasthelakelevelfell

c)Duringthelowermicrobialcarbonatedeposition,therewasasimultaneouspositiveexcursionin87Sr/86Sr,indicatingacorrelationbetweenthem

d)Microbialcarbonatedoesnotoccurinsomestratigraphichorizons,possiblyduetosamplinglocationsbeingoutsidethelake

Question29:

Satelliteremotesensingdataisincreasinglybeinggeneratedandappliedtomanyquestions,includingcarbonateformationinthemodernoceans.

FigureQ29.1presentssixrelevantglobaloceanicdatasets.

FigureQ29.1:GlobalmapofmodernoceanparametersWhichofthefollowingstatement(s)is(are)correct?

a)Moderncoralreefsaremainlydistributedneartheequatorandcoupledwithahigh-temperaturezone

b)SeasurfacewindvelocitycorrelateswithChlorophyll-a,indicatingthatcyanobacteriaareonlyregulatedbyoceancurrents

c)Anincreaseincalcitesaturationpromotestheformationofcarbonaterocks

d)Anincreaseinalkalinitywillcertainlypromotetheformationofcarbonaterocks

e)Highsalinityinmid-latituderesultsfromlessriverwaterinput

Question30:

ArecentstudysummarizedthecarbonateformationmodelintheBahamiancarbonateplatform.

FigureQ30.1:Aconceptualmodelfordepositioninacarbonateplatform

WhichofthefollowingstatementsisNOTcorrect?(onlyonecorrectanswer)

a)Carbonatesedimentcanbeproducedintheformofskeletalgrains,ooids,andlimemud

b)Ooidscanbeproducedontheplatformmargin,withintheplatform,andontheouterp