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

Figure 1

Regional tectonic setting and location of SNGF. (a) Major tectonic structures of the Philippines after Aurelio [14]. Large white arrows are plate motion directions [13, 15]. Grey arrows are the horizontal maximum compression orientations measured in Bicol in Lagmay et al. [16] and in Luzon in Yu et al. [17]. Red box represents the boundaries of the next figure. (b) Negros Island, showing the Negros volcanic arc in red triangles and the estimated trace of Yupisan Fault in dashed dark pink, overlain by the approximate boundaries of the tectonostratigraphic terranes. Red box represents the boundaries of the figure below it. (c) Simplified map of SNGF encompassing the CDN volcanic complex showing the key lineaments identified in this study (black line), course of Okoy River (blue), volcanic edifices within the complex (red triangle), and estimated location of thermal manifestations (red dots), overlain by a simplified geological map of the field from Rae et al. [18] and PNOC-EDC internal reports. Boxes (i) to (iv) are the location of the outcrops discussed in this paper. (b) and (c) overlay 90 m SRTM DEM data from Jarvis et al. [19].

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