Niniek Rina Herdianita
Lithology of Mt. Ratai-Pesawaran and Mt. Betung are dominated by Quaternary andesite lava, breccia and tuff; sedimentary rocks and schist are present in low elevations, i.e. near Ratai Bay. Older dacitic rock is exposed near Kiluan Cape, indicating an andesitic-rhyolitic magmatic evolution. Mt. Ratai-Pesawaran and Mt. Betung are separated by NW-SE faults associating with Gebang Caldera. Discharge area of the Way Ratai geothermal system shows the occurrences of surface manifestations at south to southeast Mt. Ratai-Pesawaran (i.e. as Way Urang and Way Panas hotsprings and Margodadi hotpools) and northeast Mt. Betung (i.e. as Natar warm spring and Puri Gading seepages). Siliceous sinter deposit is present at Margodadi, while travertine occurs at Way Urang and Way Panas. Water sampling and analyses of major anion-cation and 18O-D stable isotopes were carried out to understand the characteristics of thermal waters. The stable isotope study indicates that neither magmatic fluid nor seawater influenced the thermal water. Sub boiling sub surface condition causes no steam discharge to the surface as fumaroles or steam vents.
Penerapan Karya Tulis
to understand the characteristics of Way Ratai geotermal system