Palaeowaters from the Glatt Valley, Switzerland
R. PURTSCHERT1, U. BEYERLE2, W. AESCHBACH-HERTIG2, R. KlPFER2.3 & H.H.
Iphysics Institute, University of Bem, 3012 Bem, Switzerland
2Environmental Physics, Swiss Federal Institute ofTechnology (ETH), Swiss Federal
Institutefor Environmental Science and Technology (EAWAG), 8600 Dübendo1j; Switzerland
3Isotope Geology, Swiss Federal Institute ofTechnology (ETH), NO C61, 8092 Zürich,
Abstract: Isotopic and noble gasdatafrom a confinedgravel aquifer in the SwissPlateauhas
beeninvestigated. From glaciomorphologicalstudiesit is well known that the Glatt Valleywas
repeatedlyice covered during thelastglacialperiod.Correctedradiocarbonagesrangefrom O to
> 28ka BPandreveal agapof between25and17ka BP,indicating aninterruptionof groundwater
rechargeduring the last glacial maximum. Based on 39Ar measurements,a contribution of
youngerwater componentswith residencetimes of a few hundredyearshavebeenidentified in
some waters. Recharge temperatures,estimatedby analysis of noble gas contents.suggest a
temperaturedifference of c. 5°C at the Holocene-Pleistocenetransition at 12ka BP.The long-
term temporal ö180-recharge temperaturerelation over the last 30ka has a slope of c.
0.49%0oC-l. consistent with themodernseasonalrelation.
atmospheric noble gases (Mazor 1972). While