STRUCTURE IDENTIFICATION OF GEOTHERMAL PROSPECT AREA USING GRAVITY DATA GRADIENTÂ TECHNIQUES

• Main Author: Wehantouw, Sanctie
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71338
• Institution: Institut Teknologi Bandung

The Kadidia geothermal prospect area has two distinct geothermal systems. The manifestations that appear on the surface are warm soil and hot springs which are controlled by several existing structures. The structures that separate the two Kadidia geothermal systems have not been identified. In this study, analysis of gravity data for the Kadidia area was carried out to identify structures using horizontal gradient (HG) and vertical gradient (VG) techniques as well as improved normalized horizontal tilt angle (INH). Gravity data for the Kadidia area were obtained from the Pusat Sumber Daya Mineral Batubara dan Panas Bumi (PSDMBP) which conducted field surveys in 2012 and 2014. From this study, it was found that the structures in the Kadidia area are normal faults that form horst and grabens which control manifestations and form reservoirs. Horst is the boundary between the North Kadidia and South Kadidia geothermal systems, each of which is in the graben. In the graben structure, there is granite with a low density of 2.7 gr/cm3. This faulted granite is located at a depth of 750 meters and is identified as the location of the reservoir. The heat source in both systems comes from hot rocks at a depth of 5000 meters above sea level