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Geology, Paleoenvironments and the Straigraphic Position of the Wallertheim Find Horizins

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Geology, Paleoenvironments and the Straigraphic Position of the Wallertheim Find Horizins
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  REPORTS FOR THE SE OND W LLERTHEIMWORKSHOP Tubingen,March23-25,1997 aU6ingm. Edited by Nicholas J. Canard and Andrew W. KandelInstitutfurUr-undFruhgeschichteUniversitatTubingenSecondPrinting  WALLERTHEIMWORKSHOPIITubingen, March 23-25,1997 GEOLOGY, PALEOENVIRONMENTSAND THESTRATIGRAPHIC POSITION OF THE W ALLETHEIM FIND HORIZONS I PaulHaesaerts, InstituteRoyaldesSciencesNaturellesdeBelgiqueRueVautier29B-I040BrusselsBELGIUM Roger Langohr and Geo-,Archaeo-andEcopedologyResearchGroupUniversityofGentKrijgslaan281/S8B-9000GentBELGIUM Nicholas J. Conard UniversitatTiibingen Institut furUr-und Fruhgeschichte AbteilungAltereUrgeschichteund Quartarokologie Schloss Hohentubingen D-72070TubingenGERMANY The bestplacetobeginareview of the sedimentsinWallertheimiswiththework ofSchmidtgen andWagner.Intheirfigures,oneimmediatelyrecognizesthemaincharacteristics of thestratigraphy.TheseincludeTertiaryclaysatthebase of thesection;the Talwegterrasse andtheloessrestinguponit;asequence of fluviatiledepositsincludingthe Fundschicht; iron-rich,humicclays;humuswithcalciumcarbonateplates;andfinallythethickoverlyingdeposits of loess.Withfewexceptions,thegeologicalobservationsmadebySchmidtgenandWagnerhavebeenconfirmedbythecurrentresearch.Furthermore,thechronostratigraphicinterpretationpublishedin1929correspondsverycloselywiththepresentinterpretation.EventheagesproposedbySchmidtgenandWagner,basedon Soergel s (1925)publication of theMilankovitchcurve,areconsistentwithmodernchronometricdatesandotherstratigraphicarguments.Whilelaterworkhassupplementedourunderstanding of theQuaternaryprofileinWallertheim,theoriginaldescriptionprovidedresearcherswithanoutstandingstartingpoint.Ourpreliminaryresultsfromavariety of geoscientificmethodsfavorplacingthevastmajority of theWallertheimsequenceinthelastinterglacial-glacialcycle.Oldersedimentsincludethegravels of the Talwegterrasse andtheremnants of theloessfromthepenultimateglaciationthatrestuponthisterraceinthewesternpart of thesection.Stratigraphicallyoverlyingthesesediments,thoughnotnecessarilyhigherinelevation,followroughlyISm of fluviatileandloessicdeposits.Thecurrentstratigraphicsystemdividesthemainprofileintosixprimarysedimentarycycles.Cycles1-3arepart of thefluviatilesystem of theWiesbach,whileterrestrialsedimentscomprisethedeposits of cycles 4 6.Aquaticandsemi-aquaticspeciesfromthefirstthreecyclesincludepike  Esoxlucius , beaver  Castor ji er andthewatervole  Avicolaterrestrisy. Thesecyclescanbefurtherdividedtoafinerlevel of detail.Here,however,wewillconcernourselvesprimarilywiththemoresignificantaspects of theWallertheimsedimentsandtheirchronologicalandpaleoenvironmentalsignificance. Sedimentary cycle 1 beginswiththedepositionoffluviatileclaysandsiltswhichoverlythegravelsandTertiaryclayatthebase of thecentralandeasternpart of themainexcavationprofile.Here,aswithelsewhereinthefirstthreecycles,weseestronglateralfaciesshiftsfrommorefluviatiledepositsintheeasttomoreterrestrialdepositsinthewest.TheMiddlePaleolithicoccupation of findhorizonA(Figure1)liesinayellow-brownsiltwhichcorrespondstotheupperportion of thiscycleandbelongstoaperiod of aggradingfloodplainsedimentation.Casts of rootletsareubiquitouswithinthefindhorizonandindicatethepresence of agrassyvegetationatthetime of theoccupation.ThericharchaeologicalfindsfromhorizonAareinprimarycontextandshowlittleevidence of beingdisplacedbygeologicalorbiologicalforces.Thisphase of sedimentationendswiththeformation of asoilandbringscycleItoaclose.Thefindswithintheremnants of thissoilbelongtofindhorizonB(Figures1and2).Althoughitisplausiblethatthissoilisinter-Eemian,atpresent,itseemsmostlikelythatthissoilcorrelateswiththeEemianinterglacial.Faunalremainsincluding Damadama and Susscrofa fromfindhorizonsAandBsupportthiscorrelation. I ThisreportisanexcerptfromConard,HaesaertsandLangohr,  996 46  WALLERTHEIMWORKSHOPIITubingen,March23-25,1997 Sedimentary cycle2beginswiththeerosion of thesoilandthereworking of thesoilandthefindsfromhorizonBintoirregularpockets.Overlyingthesepockets,particularlyinthewesternpart of theprofile,apoorlysortedgravelfollows.Thisperiod of sedimentaryinstabilityprobablycorrespondstotheend of theinterglacialandmaybepartiallyexplainedbyalocaldeclineinvegetation.Thisgravelliesatthebase of sedimentarycycle2andincludesthereworkedfinds of horizon C. Althoughthestratigraphicprofilesfromthe1920sdifferslightlyfromthecurrentones,theplacement of Schmidtgen s Fundschicht correspondsmostcloselytothat of findhorizon C. SchmidtgenandWagner scorrelation of the Fundschicht withthefirstcoolingafterthelastinterglacial,andtheirdating of thehorizonto110-113kyrremainsentirelyplausible.Overlyingthegravelsatthebase of cycle2severalclearlydefineddepositscontainfindhorizonsD,EandF(Figure1).Thefirst of thesedepositsisaea.SOcmthick,red-brown,clay-richsiltwithinwhichliesthearchaeologicallyimportanthorizonD.Thissedimentisanalluvialdepositwhichpinchesouttothewestasoneleavesthefluviatilesystemandentersthecolluvialsystem.Movingupwardintheprofile,wenextseeea.60cm of grayclaywithcleardeposits of ironoxideandblackorganicmaterial.Thelowerportion of thisdepositcontainsarichaccumulationofbovidremainsandasmallnumber of artifactsfromfindhorizonE.Faunalpreservationin this depositisexcellent,andmoreremarkably,botanicalremainshavealsobeenrecovered.ThebotanicalremainsincludeleavesidentifiedbyF.Damblonasblackpoplar, Populusnigra. Thisspecies of treelivestypicallyinmoistdrainagesandfloodplainsduringwarmerclimaticphases.Thesefinds,alongwithpreliminarymolluscandata,supportthegeologicalargumentsthathorizonEcorrespondstoawarmclimaticphaseandthatthedepositaccumulatedonamarshyfloodplain.Atpresent,weinterpretthisasthefirstwarmperiodaftertheEemianinterglacial,whichistheequivalent of isotopestageScorSt.GermainIfromthepollensequencefromGrandPile(Kukla1977,WoillardandMook1982).However,wecannotentirelyruleoutthatthesedimentsandfindsbelongtoone of theclimaticoscillationswithintheEemianinterglacial. It haslongbeensuspectedthatthelastinterglacialincludedsignificantclimaticoscillations.ThissuspicionhasrecentlybeensupportedbydatafromdetailedoxygenisotopemeasurementsfromGreenlandandnewbotanicalstudies(GRIP1993,Dansgaardetal.1993,Fieldetal.1994).Continuingupthestratigraphicprofilewithinsedimentarycycle2,wefindtheyoungestarchaeologicalmaterialsfromhorizonF.Thesefindsfromnearthetop of thegrayclayaredominatedbyabundantfaunalremains of horse.LikefindhorizonE,relativelyfewartifactshavebeenrecoveredfromthishorizon.Thisoftenclean,homogeneous,grayclayaccumulatedinalowenergysedimentarymilieuinamarshorwetfloodplain.Themajority of findsinhorizonsD,EandFare insitu andbelongtoperiods of sedimentaryaggradation.AlongwithhorizonsDandE,wefavorcorrelatinghorizonFwiththefirstclimaticameliorationfollowingthelastinterglacial.Atpresentitappearsthatthemajority of thefaunalmaterialfromhorizonsEandFaretheresult of naturalpaleontologicalaccumulationsindependent of hominidactivitiesintheWiesbachdrainage.Cycle3beginswithasiltysheet-washandsplashdepositonabaresurfaceorashallowpond.Atthistimeanerosionaleventisrecordedinthecentralportion of themainprofilewhereadepression1015mwideandlmdeepisreadilyvisible.Thebase of thisdepressionisfilledwithcross-beddedsands.Siltsandclaysthatoriginatefromthedeposits of cycles1and2andthesilty,whitesplashdepositsfromthebase of cycle3filltheupperportion of thedepression.BoringsbyJ.Preuss teamhavedemonstratedthatthisdepressioncanbefollowedmanytens of metersintothesedimentssouth of theprofile.Intactsedimentsfromcycles1and2areclearlyvisibleonboththeeasternandwesternsides of thedepression.Thiserosionaleventmayhaveresultedfromthedegradation of apermafrost.Followingtherapidfilling of thedepression, ahydromorphic soildocumentsapoormarshvegetation.Thissoilischaracterizedbylarge,verticallyoriented,ironoxide-filledbiogalleriesoccurringwithinastratifiedbrownsilt.Thetop of thissoilcorrespondstotheend of sedimentarycycle3.Withthestart of cycle4,weenteraterrestrialsystem of sedimentation.Hereamixtureofhumiferouseolianandcolluvialsiltandsandwasdepositedonagrasscoveredsurface.Thesesediments 47  WALLERTHEIM WORKSHOP1ITubingen,March23-25,1997 correspondtoaperiod of verydryandcoldconditions. The depositcontainsobviousstratificationwith many recognizablebrownsiltbandsandareaswithvisiblemicrolayers of loess.Thesedepositsare not horizontal,butratherslopedownwardslightlyfrom west toeast.Noteworthyarethemany thick calciumcarbonateplates that followtheslope of thebeds. The ea.3m thickhumic depositsareeasilyidentifiedintheprofiles of W. Wagner andotherpublicationsaboutWallertheim.Wetentativelycorrelate the deposits of cycle3withisotopestage5band the deposits of cycle4withisotopestage5a. Cycle 4endswithextremelycoldanddryconditionsduringwhichseveralcycles of permafrostproducedthermalretractioncracksextendingmorethan two metersinto the underlyingsediments.Wecorrelatethiscoldphasewith the start of isotopicstage4.Subsequently,loessblewoverthisbareornearlybaresurfaceandfilledthecracks. Sedimentary cycle5 beginswiththedeposition of loessuponwhichaweaklydevelopedchernozemforms.Evidence of freezingand thawing ispreserved,but there isnoevidenceforpermafrost. The top of thissoilisthenerodedfollowedby the deposition of stratifiedsilt,sandandveryfinegravel. Cycle6 coincideswith theonset of MiddleWeichselianloessdeposition.Withinthemainprofileapale gray tundrasoilispreservedintheeastern part of the exposureandcorrespondstoacoldclimaticphase.Thedepositsfromallsixsedimentarycyclesare cut byaseries of faultswhichdisplacethesedimentsbyseveraltens of centimeters. The genesis of thesemultiplefracturingandthrustingeventsisnotclear,but most plausibleexplanationsincorporateeithertectonicorpermafrostprocesses. REFERENCES Conard, NJ., P.Haesaertsand.R.Langohr.1996.Quaternary Geology andPalaeolithicArchaeologyinWallertheimlRheinhessen. Frankfurtergeowiss.Arbeiten D,20:131-141.Dansgaard,W.S.,J.Johnsen,H.B.Clausen,D.Dahl-Jensen, N. S.Gundestrup, C. U. Hammer, C. S.Hvidberg,J.P.Steffensen, A. E.Sveinbjornsdottir,J.JouzelandG.Bond.1993.Evidenceforgeneralinstability of pastclimatefroma 250-kyr ice-corerecord. Nature 364:218-220.FieldM.H., B. HuntleyandH.Muller.1994. Eemian climaticfluctuationsobservedinaEuropeanpollenrecord. Nature 371:779-783.GreenlandIce-coreProject Members (GRIP).1993.Climateinstabilityduringthelastinterglacialperiodrecordedinthe GRIP icecore. Nature 364:203-207. Kukla G.1.1977.Pleistoceneland-seacorrelations.   Europe. Earth-ScienceReviews 13:307-374.Schmidtgen,O.andW. Wagner 1929.EinealtpalaolithischeJagdstellebeiWallertheiminRheinhessen. NotizblattdesVereins fur Erdkunde un derHessischenGeologischenLandesanstaltzuDarmstadt 11:1-31.Soergel,W.1925.Die Gliederung undabsoluteZeitrechnungdesEiszeitalters(Berlin).WoillardG.M.andW.G.Mook.1982.Carbon-14DatesatGrandPile:Correlation of LandandSeachronologies. Science 215:159-161.48  WALLERTHEIMWORKSHOPII Tubingen, March 23-25,1997 Figure1.Wallertheim.Thelocation of the village of allerthe imandamap of the oldbrickyard.   o   Scale11000 SOm ~ - •I  0 ) 49 Legend 1991-94-ExcavationBrickfoundations  -..... Fence
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