A remote sensing study of the Northern Negros Geothermal Project (NNGP) was conducted using Airborne Synthetic Aperture Radar (AIRSAR) images that have the ~ 10 - meter spatial resolution of traditional aerial photographs. A digital elevation model (DEM) was generated from the topographic SAR (TOPSAR) data sets while the general surface geology was extracted from the polarimetric SAR (POLSAR) data sets.
Northwest - trending lineaments form the dominant structural grain in the study area. This tectonic fabric is expressed by lineaments with the following trends: northwest (293° - 337°), west - northwest (270 ° - 292°) and north - northwest (338° - 360°). The northwest and west - northwest structures control the occurrence of thermal springs (e.g. Mambucal thermal area and Hagdan hot spring, respectively) while the north - northwest structures are associated with the distribution of volcanic vents and are strongly related to the eastward subduction along the Negros Trench. In addition, nine geologic units were outlined within the study area as volcanic products generated from the Canlaon Volcano.
Major structures such as Catugasan - C, Mambucal - A and Asia Splay A faults which were intersected by Pataan boreholes PT-1D, PT-2D, PT-3D and PT-4D represent the major permeable zones in the wells. It is prudent to target similar - trending structures for future production and reinjection purposes.
The integrated results of the geological, geochemical and geophysical surveys indicate that the upflow of the geothermal system is within the Hardin Sang Balo area. The upflow is structurally - bounded by the southeastern segments of Mambucal - A and Asia Splay Extension while the outflow is channeled along the Catugasan - C and Catugasan - B Splay faults towards NW in the general direction of the Kinabkaban warm spring and Mambucal thermal area.
Drilling towards the east - southeast direction (from Pataan - B pad) is favored to intersect high temperature geothermal fluids and to test the postulated hydrological model of NNGP.