Geochemical Investigation of Milos Geothermal Field in Greece

Abstract

A revised interpretation of old geochemical d a t a toge t h e r with ana lys i s of new information from deep wells i s presented i n t h i s paper. The hydrological model of Milos field is which consists of two distinct hydrological systems. The deep geothermal fluid of high salinity (45000 ppm C l ) o r i g i n a t e s from s e a water (21000 ppm is enriched i n because of b o i l i n g and steam loss and outflows again below t h e sea There are almost no manifestations of it t h e s u r f a c e . On t o p of it i n shallow aqui f e r s lies a steam heated r i c h f l u i d of l o w s a l i n i t y which o r i g i n a t e d f r o m meteoric waters wi th sea water mixing o n l y l o c a l y near t h e coast. Near t h e s u r f a c e a c i d f l u i d s causing advanced a r g i l l i c a l t e r a t i o n can be found i n some areas. These t w o types o f f l u i d supply t h e thermal m a n i f e s t a t i o n s on t h e i s l a n d .