THE ROLE OF FRACTURE DENSITY IN MANIFESTATIONS OF UPFLOW AND OUTFLOW ZONES OF A UNGARAN MOUNTAIN GEOTHERMAL SYSTEM

Abstract

Geothermal exploration requires the identification of upflow and outflow zones in geothermal resources, especially when determining the best drilling locations. As a Geothermal Working Area (WKP), Mount Ungaran in Central Java is still unexplored.  Understanding this region's geothermal system necessitates a comprehensive strategy that combines geochemical and structural research. This study uses geochemical indicators (HCO3, Na/K, and CO2) and fracture density (Fault Fracture Density, or FFD) analysis to identify the upflow and outflow zones.  Geothermal fluid flow may be influenced by areas with high structural density that are identified by FFD analysis. These zones are made up of interconnecting faults and fractures. Geothermal flow zones can be more precisely defined by using geochemical indicators, which offer more information on the properties of subterranean fluids. The findings show a high link between FFD and geochemical indicators, corroborating the initial theory that the upflow zone is most likely situated in the crater area close to Mount Ungaran's volcanic body.  Future drilling recommendations in Mount Ungaran are based on this study, which emphasizes the value of combining structural and geochemical techniques in geothermal exploration.