Rareearthsandyttriumhydrostratigraphyalongthe LakeKinneret–DeadSea–Aravatransformfault, Israelandadjoiningterritories P.Mo¨ller a, *,E.Rosenthal b ,P.Dulski a ,S.Geyer c ,Y.Guttman d a Geoforschungszentrum Potsdam, Telegrafenberg, D-14473 Potsdam, Germany b Department of Geophysics and Planetary Sciences, Tel Aviv University, 69978 Tel Aviv, Israel c Department of Hydrogeology, UFZ-Center for Environmental Research Leipzig-Halle, D-06120 Halle/Saale, Germany d Hydrology Department Mekorot Water Co. Ltd., POB 20128, Tel Aviv 61201, Israel Received22July2002;accepted7February2003 EditorialhandlingbyR.Fuge Abstract RareearthelementsandY(REY)havebeenanalysedin49groundwatersfromlocalitiesintheareasofLakeKin- neretandtheJordanandAravaValleys.ThesewatersoriginatefromvariousaquifersandtheREYabundancesare expectedtobecontrolledbytheaquiferrocks.TheREYpatternallowonetodistinguishinteractionofwaterswith basalts,basalt-limestoneinteractionzones(silicifiedlimestones),limestonesfromtheJudeaandAvdatGroups(Upper CretaceousandEocene,respectively),andsandstonesoftheLowerCretaceousKurnubGroup.Groundwaterfromthe Quaternary alluvial fill (Dead Sea Group) are either controlled by Judea Group limestone or Kurnub Group sand- stone.TheREYpatternsshowcharacteristicfeaturesforeachgroup.Inhydrogeologicalsystems,therocksofnatural replenishmentareasareusuallynotthesameasrockunitsfromwhichthewatersarecollected.Thisbecomesevident by comparing the lithostratigraphic groups from which the waters were collected and the hydrochemical grouping accordingtoREYpatternswiththeircharacteristictrendsandanomalies.Inmanycases,thereisacorrespondence between the lithostratigraphic and the hydrochemical grouping; in other cases, the 2 groupings disagree. This dis- agreementprovesinter-aquiferflowofgroundwater.Insomecases,thegeologicallyderivedaquifersrocksoforigin, differ from those indicated by REY patterns. Thus, applying the REY grouping, new fundamental information for hydrologicalmodelscanbegivenandsourcesofsalinisationcanbeelucidated. # 2003ElsevierLtd.Allrightsreserved. 1. Introduction Apart from their application in petrology and sedi- mentology,rareearthelementsandY(henceforthcom- binedtoREY)arenowrecognizedasapowerfultoolin the study of low-temperature water–rock interaction (e.g. Smedley,1991;Mo¨ller,2000).Theoccurrenceand the distribution of REY has been studied in ground- water (Banks et al., 1999; Johannesson et al., 2000; Mo¨ller,2002),inthermal-(Michard,1989;Lepeletal., 1989; Kikawada et al., 1993; James et al., 1995; Klin- khammer et al., 1994; Mo¨ller, 2002), mineral- (Mo¨ller, 2000), river- (Banks et al., 1999; Johannesson et al., 1999; Bau and Dulski, 1996) and in ocean-waters (Elderfield,1988;Mo¨lleretal.,1994).TheREYpatterns ofwatersrarelycoincidewiththoseofassociatedrocks or sediments. Exceptions are river- and groundwaters originating from low-clay limestone/dolomite environ- ments (Johannesson et al., 1999; Mo¨ller, 2002). The reason for the observed differences in REY abundance andtypeofREYpatternisthataconsiderablefraction of REY is released from accessory minerals among 0883-2927/03/$-seefrontmatter # 2003ElsevierLtd.Allrightsreserved. doi:10.1016/S0883-2927(03)00044-1 AppliedGeochemistry18(2003)1613–1628 www.elsevier.com/locate/apgeochem * Correspondingauthor. E-mail address: pemoe@gfz-potsdam.de(P.Mo¨ller).