A structural model guide for geothermal exploration in Ancestral Mount Bao, Leyte, Philippines

The Tongonan Geothermal Field, located on the eroded flank of Ancestral Mount Bao (AMB) volcano, is the largest producing geothermal field in the Philippines. It produces about 640 MW of energy supplying power to the grid of Luzon, Visayas, and Mindano, the three major islands of the Philippines. The Tongonan geothermal field is host to several major power plants that tap geothermal power from the northern flank of the AMB volcano. I present a structural model guide for delineating exploration targets in other flanks of the ~1,200 km2 area of the AMB volcano. The model limits the exploration area, where more detailed investigations involving geophysical, and geochemical methods can be applied. This structural model guide is based on analogue sand cone experiments, their comparison with the natural prototype (i.e. AMB volcano), and the observation of the geographic positions of producing geothermal power plants within the Tongonan Geothermal Field. Based on this structural model, I suggest an ideal exploration target on the south-southeastern flank of the AMB, directly overlying the left-lateral Philippine fault.