Subsurface Modeling Using Gravity Data in the Geureudong Volcano Geothermal Prospect Area

Mount Geureudong is located in the Bukit Mulie area, Bener Meriah Regency, Aceh Province. This study aims to interpret the subsurface lithology of Mount Geureudong and develop a two-dimensional model. The data utilized in this research are secondary satellite data from GGMplus (gravity disturbance) and elevation data from ERTM2160. Inversion modeling was carried out using Grablox software, with residual anomaly data that had undergone flat-surface reduction. The inversion process resulted in 2D density cross-sections along the x, y, and z axes, visualized using Surfer software. The modeling suggests the possible presence of andesite rocks with densities of 2.4–2.8 g/cm³, lava at 2.9 g/cm³, pumice at 0.8–0.9 g/cm³, basalt at 3.1–3.3 g/cm³, sandstone at 2.0–2.3 g/cm³, soil at 1.3–1.8 g/cm³, and gabbro at 3.4–3.5 g/cm³. The 2D modeling of the Mount Geureudong study area indicates that andesite and sandstone are the dominant rock types, distributed across the region with density values ranging from 2.4 to 2.8 g/cm³. Keywords: Mount Geureudong, Gravity, GGMPlus, Density, Inverse Modelling