UNDERSTANDING THE HYDROLOGICAL PROCESSES OF THE BERLIN GEOTHERMAL FIELD, EL SALVADOR, BASED ON STABLE ISOTOPE DATA

Abstract

The isotopic investigation carried out in the Berlin geothermal field, indicates that the upflowing geothermal fluid represented by 618O and 62H of -3.4%
and -43% was intersected by well TR-5. The relationship between 618O and C1 indicates that steam separates at various proportions and temperature as the fluid ascends to the surface. The residual liquid characterized by heavier isotope contents are tapped by wells TR-9, 2 and 3. The steam is postulated to find its way into the numerous fumaroles common in the Berlin geothermal field. TR-5 as well as the rest of the other wells, are recharged by meteoric waters likely with 618O and 62H of -7 % and -49 %, respectively, which remains to be validated by additional isotopic measurements from meteoric and geothermal waters. A mixing line connects the meteoric end member and the geothermal waters at a slope which indicates that the parent source water is heavier in stable isotopes, likely andesitic in composition.