Interpretation of the gravity and magnetic anomalies of the geothermal subsurface structure area in Pamancalan, Lebak, B
- PDF / 9,140,043 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 122 Downloads / 204 Views
ORIGINAL PAPER
Interpretation of the gravity and magnetic anomalies of the geothermal subsurface structure area in Pamancalan, Lebak, Banten, West Java, Indonesia Sismanto Sismanto 1 & Uji Yasmita 2 & Fitri Jusmi 3 Received: 29 November 2017 / Accepted: 16 July 2018 # Saudi Society for Geosciences 2018
Abstract Pamancalan is located in Lebak Regency, Province of Banten. This area is located in the western part of Java Island, Indonesia. The geothermal manifestation in this area is in the form of hot spring in Cipamancalan River. But, how the structure of the geothermal system, the reservoir depth, and the thermal source in the Pancamalan area has not been studied much. Therefore, there is a need to conduct a geophysics study by surveying the gravity and magnetic field. A study, which used magnetic and gravity data to discover reservoir, has been conducted in the Pamancalan geothermal area in Lebak, Banten. Topographic map for total magnetic and earth gravity anomaly shows that the anomaly is located in the center and southern part of the presumed reservoir. 2.5-D section model of magnetic anomaly shows that there is a rock formation which shaped the geothermal system in Pamancalan. The thermal source is diorite which is a by-product of Hanjawar Mountain; the reservoir rocks consist of sandstone, limestone, and breccia; and the cap rock is in the form of clay and tuff. It is predicted that there is an intrusive body which functions as thermal source in the depth between 1650 and 4000 m, the reservoir depth is around 700 m, and the depth of clay cap is around 0 to 700 m. The geothermal manifestation in Pamancalan area is controlled by Cigeledug fault from the southwest and Cipamancalan fault from the north and south. Keywords Gravity and magnetic data . Geothermal . Pamancalan . Spectrum analysis . 2.5-D and 3-D modeling
Introduction The Pamancalan geothermal area is located in 6°45′5″ S– 6°53′11″ S and 106°12′51″ E–106°21′0″ E, and is located in
* Sismanto Sismanto [email protected] Uji Yasmita [email protected] Fitri Jusmi [email protected] 1
Geophysics Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta, Indonesia
2
Physics Department, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta, Indonesia
3
Physics Study Program, Faculty of Science, Cokroaminoto University, Palopo, Sulawesi Tenggara, Indonesia
Zone 48 of the UTM system with total area of 15 km2 (Fig. 1). The study area is part of west Java province that located 25 km south of Endut Mountain. In this study, geothermal subsurface structure in Pamancalan is studied by means of interpretation of gravity and magnetic anomalies. In geothermal exploration, gravity and magnetic method are generally used to delineate the subsurface structure which controls the geothermal system (Nouraliee et al. 2015). Combination the gravity and magnetic data can reduce the ambiguity of understanding subsurface structure, produce a more robust interpretation, and provid
Data Loading...
