REGIONALSETTING

TheSantaAgueda–PozaRicaplatform-to-basindepositionalsystemislocatedinthesouthwesternpartofthelargerCre-taceousGoldenLaneplatformineasternMexico.TheGoldenLaneplatformisoneofseveralisolatedCretaceouscarbonateplatformsthatdevelopedonaseriesofhorstblocksinthewesternGulfofMexico(GOM)duringtheAlbian(BarnetcheandIlling,1956;ViniegraandCastillo-Tejero,1970;Cooganetal.,1972;Enos,1977;Wilson,1990;McFarlanandMenes,1991;Goldhammer,1999).DuringtheEarlyCretaceous,theGoldenLaneplatformwasanellipsoid-shapedrimmedcarbon-ateplatform(Figure1)approximately150km(～93mi)widealongthelongaxisinasouth-southeastorientationand70km(43mi)widealongtheshortaxis(ViniegraandCastillo-Tejero,1970;Cooganetal.,1972).SantaAguedafieldislocatedonthesouthwest-facingmarginoftheGoldenLaneplatform,whereasPozaRicafieldislocatedontheadjacenttoeofslopeandbasinfloor,approximately6km(～4mi)basinwardofthemargin(ViniegraandCastillo-Tejero,1970;Enos,1977).

TheGoldenLaneplatformdevelopedonahorstblockformedduringJurassicrifting,whichseparatedthenarrowChicontepec–MisantlaBasintothewestfromtheGOMtotheeast(Figures1,

2).ItisunderlainbyathicksynriftandpostriftJurassicinter-val.ThebaseoftheLowerCretaceousconsistsofthewide-spreadbasinalcarbonateofthelowerTamaulipasFormation,overlainbytheargillaceousshaleoftheOtatesFormationthatcorrespondstotheAptianLaPenaandPearsallformationselse-whereintheGOM(Enos,1977).TheupperAptiantoAlbianupperTamaulipas,adiachronousformation(Enos,1977)thatcorrespondstoretrogradingouter-rampdepositsatthebase,isthebasinalequivalentoftheshallow-watercarbonatefaciesoftheElAbraFormationandtheirslopeandtoe-of-slopede-brisoftheTamabraFormationduringthelateAptiantoAlbian.BytheendoftheEarlyCretaceous,theisolatedGoldenLaneimprovementofhandlingoftechnicalinforma-tioningeophysicsforthePozaRicaandChi-contepecgroupswithinPEMEX.HehasalsobeenateacheratUniversityVeracruzanasince1986.ACKNOWLEDGEMENTSThisstudyispartofanintegratedreservoircharacterizationcollaborativeprojectbetweentheBureauofEconomicGeologyandPemexExplorationProduction.WethankthedirectorsofPemexExplorationandProductionforal-lowingustopublishthisstudy.WethankournumerouscolleaguesattheBureauofEconomicGeologyandatPemex,whohaveparticipatedindiscussionsontheseredepositedcarbonatesediments.ThemanuscriptbenefitedfromcountlessdiscussionswithTedPlaytonaboutcarbonateslope.WegratefullyacknowledgetheLandmarkGraphicsUniversityGrantProgramforprovidinginterpretationsoftware.DallasDunlap’shelpwasinvaluableinbuildingtheLandmarkprojects.LanaDietericheditedandvastlyimprovedthelanguageofthemanuscript.CarefulandinsightfulreviewbyGregorEberli,MikeGrammer,JereonKenter,andMarcelloMinzonimadethemanuscriptmorepertinentandfocused.TheReservoirCharacterizationResearchLaboratoryprovidedfundstocoverthecolorfigureexpenses.Publicationisau-thorizedbytheDirector,BureauofEconomicGeology.TheAAPGEditorthanksthefollowingreviewersfortheirworkonthispaper:GregorP.Eberli,MichaelGrammer,JeroenKenter,andMarcelloMinzoni.

Jansonetal.107

Figure1.(A)RegionalpaleogeographicmapshowingthelocationoftheLowerCretaceousplatformsandbasinsbasedonWilsonandWard(1993),Lehmannetal.(1998),andKerans(2002).Thedark-graynorthwesttosoutheastbandindicatesthepositionoftheSierraMadreOrientale.TheredrectangleindicatesthelocationofthemapshowninpanelB.(B)LocationofPozaRicafieldontheeastcoastofMexico(Galicia(2000).(C)RegionalschematiccrosssectionofGoldenLaneplatform.ModifiedfromCooganetal.(1972)andChenetal.(2001).Chenetal.(2001)andGalicia(2000)figuresarerepublishedwithpermissionfromtheGulfCoastAssociationofGeologicalSocieties.108SeismicArchitecture,SantaAguedaandPozaRicaFields,Mexico

,ygrineannthetenmendnhwey-eoewmttesaswohbtddoeierngetlSokcecopountiui.ethwlirsasriatissodswsa.

/sosllgsnepaanieoeeoinepntne,iodomodwtulst”mebtsssodndppdeyrtotuuarfutioudemsmendmnotaooclhenisbapti.

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combabstliihsouae,stesalraTedzsms)uvienaestfgrerganThuiTieheiorr5Ftttcrae.n1(nidaelhele(nnrttgioaifrmokcaaihioadnhirthecrhse5aTvettieloerg,ssm.aewisdarosbatlselieaafnihFsslencuvcs.ciroaruaemavrprcetmbestg-aoFreratpensieespvnieglnniamalemfonaortdTaueoesyrunNspvdemeoThshi.,euvtatiasmrtelsuminafogFateasftoimepAansuolserinroetidekshcotabmunscesoyacgdrnepgfmylroaooirramefdeToneeyinscntaleepemilfhmnotdcocrythisefrettos-kd.otwkwcosuwidsnocoyllantmoryrloaoreelpsybthpensuniaebnidemubdddnnagomnaomananudanmlreodiost,cfeisaaetogngrkifsirsnicnhlitusroeeecpeslltgpemainornmsroseddtlubdaaeypaolbtmonihrcSTe

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cnaotws/deunomtssduuomneegimrrieLTplatformbuiltupto1200m(3937ft)ofrelief.TheTamabraisoverlainbythethin-bedded,chalky,basinallimestoneoftheTuronianAguaNuevaFor-mation,whichisinturnoverlainbyotherUpperCretaceousdeep-waterfacies.TheElAbraForma-tionintheGoldenLaneisunconformablyoverlainbyTertiarydepositsintheSantaAguedafield.IntheinterioroftheGoldenLane,theUpperCreta-ceousintervalispreserved.Ultimately,theentireCretaceoussectionisoverlainbyathick,prograd-ing,siliciclasticTertiarysuccessiondepositedintheforelandbasinoftheSierraMadreOrientalorog-eny.TheGoldenLaneplatformwastiltedwest-wardduringthemiddleTertiarytectonic-relatedsubsidenceoftheGOMandSierraMadrecollision(Cooganetal.,1972).RegionalStratigraphy

AlbianandCenomaniantimesintheGOMcor-respondtoaglobaleustaticrise(Haqetal.,1987),reachingapeaktransgressionofthePhanerozoicintheTuronian.Thelong-termriseduringmiddletolateAlbianisconsistentwiththeaggradationalstackingpatternofcarbonateplatformsandmini-malinfluxofsiliciclasticsedimentintothebasinthroughouttheGOM(McFarlanandMenes,1991).Lehmannetal.(1998)completedadetailedse-quenceframeworkoftheAlbiansectioninanAlbianplatformtimeequivalenttotheGoldenLaneplat-formintheCoahuilablockandrecognizedthreecompositesequences(Figure2).Similarly,theCo-mancheShelf–StuartCitysysteminsouthTexasisthenorthwardextensionoftheAlbiancarbon-atesystemsofMexico(BeboutandLoucks,1977;WilsonandWard,1993;Yurewiczetal.,1993;Lehmannetal.,1998).Loucksetal.(inpress)syn-thesizedstratigraphicdataforthe1200m(3937ft)ofsectiontimeequivalenttotheGoldenLaneplatformontheComancheshelfonthebasisoftheliteratureandoriginalinvestigations(Figure2).Theyrecognizedfourcompositesequences:(1)latestAptiantoearlyAlbian(Aptian–Albian1),(2)mid-Albian(Albian2),(3)midtolateAlbian(Albian3),and(4)latestAlbian(Albian4).

ComparisonsbetweenthelargerGOMsequenceframeworkandstratigraphyoftheTamabraFormation

Jansonetal.

111

Figure3.Layoutofseismic

datasetsavailableforthisstudy.

Twograyrectanglesshowloca-

tionandextentofthetwo3-D

seismicdatasetsusedinthis

study.Thinblacklinesindicatethe

locationoftwo2-Dseismiclines

usedtobuildregionalseismic

sectionsofFigures7,8.Redlines=

locationofvariousseismicsec-

tionsdiscussedinthisarticle.Blue

line=locationoftworegional

sectionsofFigures8,9,whereas

twogreenlines=locationofseis-

micsectionsusedforcomparison

withcore-basedcrosssections

ofFigures21,22.Circle=wells

showninFigures4,6,21,22.

atPozaRicadefinedbyLoucksetal.(inpress),aswellastheinformalsubdivisionusedbyPemex(F,A,BC,D,anda/bunits),areshowninFigure2.LithofaciesandStratigraphicArchitectureoftheElAbraandTamabraFormations

TheTamabraFormationdeep-waterdepositscon-tainfivegenerallithofaciesgroups:(1)carbonatebreccia,(2)coarse-grainedcarbonatepackstoneandgrainstone,(3)veryfinegrainedlimegrainstone,

(4)limemudstoneorwackestone,and(5)terrige-nousmudstone.Individuallithofaciesgroupscom-monlystacktoformthickamalgamateddepositstensofmetersthick,andtheyarealsointerbeddedwithoneanother.Eachlithofaciestypepossessesarangeofcharacteristics,asdescribedinTable1.TheinterpreteddepositionalmechanismfollowsMulder

112andAlexander(2001)terminology.FaciesoftheElAbraFormationconsistmostlyofrudistrudstoneandboundstoneandmiliolidpackstonetowacke-stone,aswellaskarstbreccia(ViniegraandCastillo-Tejero,1970;R.G.Loucks,2004,personalcom-munication).ForamoreextensivedescriptionoftheGoldenLaneplatformmarginfacies,seeViniegraandCastillo-Tejero(1970),Enos(1977),andChenetal.(2001).VerticalstackingoffaciesintheTamabraFormationinPozaRicafieldisillustratedincoredescriptionofwellA(Figures3,4).Onthebasisofmodernexamples(e.g.,CrevelloandSchlager,1980;Grammeretal.,1993)andan-cientexamples(BrownandLoucks,1993;EnosandStephens,1993;PlaytonandKerans,2002;Jansonetal.,2007;Playton,2008;Playtonetal.,inpress),wehavefoundapredictiverelationshipbetweenpositionwithinthesequenceframeworkand