| Abstrak/Abstract |
The Flores Island is located at the transition zone between Sunda and Banda arc that is characterized by the change of tectonic regime from the subduction of the oceanic crust in the west to the collision of the continental crust in the east. As a part of the volcanic arc, Flores Island has mostly been built by volcanic activities since Miocene. The volcanic arc in Flores Island that has been migrating trenchward in the last 7 Ma. It is in contrast with the general volcanism of the Sunda-Banda Arc that has migrated northward. Based on its tectonic regime, volcanism, and structural trend, the Flores island is segmented into two segments, west, and east Flores. In the western half of Flores, the Oligocene-Late Miocene volcanism formed in an extensional regime due to the opening of the Flores and Savu basins, where the volcanism mainly occurs in the northern part of the island. The Pliocene to recent volcanism in the western half of the island has been controlled by a compressional regime due to the Indo-Australian continental crust collision, which distributed to the south of the previous volcanism period. The dominant trend of the geological structure in the western half of Flores is mainly ENE-WSW direction parallel with the trend of the Flores Basin opening. In the eastern half of the island, the volcanism has not been shifted. The distribution of the volcanoes in the east Flores are aligned progressively in series of en echelon segments eastward with the dominant trend of geological structures NNE-SSW. 14 geothermal prospects in the Flores Island have been identified by the Ministry of Energy and Mineral Resources (MEMR), through the Indonesian Government Geothermal Development Acceleration Program in Eastern Indonesia. These geothermal prospects are mainly spatially associated with volcanic centers. In the western and central parts of the island, the geothermal prospects are associated with both Tertiary and Quaternary volcanic complexes, in contrast to those in the eastern part which is associated with the Quaternary single volcanic chain. This evidence shows that different assessment approach needs to be applied in developing the geothermal prospects in different parts of the island. |
