| Title | Fracture Characteristics of Mount Pandan Geothermal Complex, East Java, Indonesia |
|---|---|
| Authors | Wisnu Wijaya JATI, Nindyan AGNA, Lucky Kriski MUHTAR, SURYANTINI |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Mount Pandan, Geothermal, Manifestation, Fracture |
| Abstract | Fracture characterization and geological mapping had been performed in Mount Pandan area, East Java, Indonesia. This study area is composed by Tertiary sedimentary and Quartenary igneous rocks. Mount Pandan is one of an extraordinary stratovolcano in Java Island. It located in the middle of Kendeng Basin and in the north of Quartenary and Recent Volcano in Java Island. A total of 765 shear fractures have been measured and analyzed in different lithologies and age. The common fracture orientations are NW - SE, W - E, and NE – SW trends. Fractures developing in Mount Pandan area controlled by Kendeng thrust fault, sinistral and dextral strike-slip fault, and normal fault. Fractures intensity and density also controlled by lithology in this area. Fracture intensity and density in Kalibeng marl is higher than other lithologies. 12 manifestations are mainly controlled by E-W trust fault, NE-SW sinistral fault, NW-SE dextral fault. This fault becomes main porosity for geothermal fluid storage and flow. Fault Fracture Density (FFD) method was conduct to understand the correlation between fault and manifestation. The manifestation occurrence in high density value ranges between 0.002 – 0.0039 m/km2. The best way to distribute fracture in study area is by using model which built from discrete fracture network. Discrete fracture network aims to determine fracture porosity by using field data. The value of fracture porosity is varied from 0 – 0.0029 m3/m3 (0 – 0.29 %) with average porosity 0.0002 m3/m3 (0.02 %). This study is used to be an analogue of fault, fracture distribution and characteristic of Moun Pandan. Hopefully, the result of this study can be used for Mount Pandan geothermal development. |