Dear Lora,

look e.g. into the book "Environmental Isotopes in Hydrogeology"
(by Ian Clark, Peter Fritz, 1997), pages 256-258, 262-263

There you can find a short review of explanations for those
waters with isotopic data plot above meteoric water line.

Best wishes Istvan

--
Dr. FO'RIZS,  Istva'n
MTA Geoke'miami Kutato'laborato'riuma                Telephone: 36-1-319-3119
Laboratory for Geochemical Research                  Facsimile: 36-1-319-3145
Hungarian Academy of Sciences
1112 Budapest, Budaorsi ut 45
Hungary