Tectonic Evolution of the Southern Negros Geothermal Field and Implications for the Development of Fractured Geothermal Systems

Figure 11

Structural evolution of the Southern Negros and the SNGF. (a) Simplified diagram of the tectonic evolution of the Cuernos de Negros volcanic complex and its relationship with the key regional structures in the Philippines (i.e., Philippine and Cotabato Faults). (i) to (iv) represent a progressive evolution with increasing time. (b) For SNGF, the model focuses on the three stages of fracturing. Apparent changes in stress directions suggested in the palaeostress inversion which could be a function of small-scale block rotation are indicated. Note that the sketches are not drawn to scale. The stereonets and the Mohr circles are generated in MyFault. Stage 1 at the local scale is contemporaneous with (i) at the regional scale, whilst stages 2a and 2b occurred during (iii) and (iv) at the regional scale, respectively.

(a)

(b)