| Abstract |
Semi-detailed geologic mapping and sampling of thermal waters and gases were conducted in Mt. Cabalian and its vicinity to determine the geothermal potential of the Southern Leyte Geothermal Project (SLGP). The rock sequences at SLGP include Late Cretaceous serpentinites, Early, to Mid Tertian, limestones, Mid to Late Tertiary clastics capped by coralline limestones, and Late Tertiary to Quaternary andesitic to dacitic volcanics and minor intrusives of dacitic, andesitic and microdiorite composition. Two major splays of the Philippine Fault - the Catmon-Bisay Fault and the Hindagan Panian Fault - and several other minor faults traverse the area, sonie of which are potential permeable drilling targets. The geochemistry of spring waters and gases indicate a near-neutral to neutral -pH reservoir fluid having a chloride content of 2500 mg/kg and a minimum temperature of 200░C. Sub-surface boiling of the deep fluids is suggested by the elevated CI concentration, high SO4 content of the springs and by the presence of several kaipohans around Mt. Cabalian. Geological and geochemical data indicate a viable geothermal resource probably centered and upflowing beneath Mt. Cabalian. Preferential outflows are postulated to the northeast along Mahalo, Mahalo--A and Mahalo Splavfaults and to the west along Nava, Hitunlob and Anislag faults. |