Overview of Gedongsongo Manifestations of the Ungaran Geothermal Prospect, Central Java, Indonesia: a preliminary account

Gedongsongo surface manifestations of the Ungaran geothermal prospect in Central Java, Indonesia, have high temperature properties, 72- 870C, 2 – 6 pH and 770 ppm of chloride. The stable isotopic ratios of δ18O and δD of two adjacent manifestations show a slightly different enrichment. The western part reveals a more magmatic water influence than those of the eastern one. This is supported by the presence of relic manifestations as most occurs in the eastern part; whereas active fumaroles and steaming ground exist at western part