| Title | 1-D Magnetotelluric Characterization of Mindanao Geothermal System, South Central Mindanao, Philippines |
|---|---|
| Authors | David M. Rigor, Jr., Carlos F. Los Banos, Domingo B. Layugan and Lauro F. Bayrante |
| Year | 2007 |
| Conference | PNOC-EDC Geothermal Conference |
| Keywords | |
| Abstract | New MT data encompassing 100 km2 of the Mt. Apo Natural Park have delineated a NW-trending shallow electrical basement between the western flanks of Mt. Apo and eastern slopes of Mr. Zion. The northeastern segment of the MT anomaly is located within the Sandawa Collapse, a zone characterized by high measured temperatures (>300oC) and shallow intersection of the anomaly covers the area beneath Mt. Zion, Lake Macadac and the southern slopes of Mt. Apo. Overall assessment of the geothermal resource coverage indicates a potential area of at least 6 km2 to the southeast outside of the Sandawa sector or a potential 170 Mwe. The new area is in addition to the current ~16 km2 exploitable resource estimated to contain a maximum of 460 Mwe total reserves. The <30-m conductive zones located around the MT anomaly signify the arbitrary outer margins of the resource. The most widespread low resistivity region mapped in the northwest characterizes the major outflows towards Agco, Imba and Marbel thermal springs. The conductive zones south and west of Mt. Zion are interpreted to be indications of possible minor outflows to the southwest towards the Bulatukan hot springs. The Kapatagan anomaly, delineated by previous SRT and VES data southeast of Mt. Apo, appears to be a signature of another outflow path to the southeast. In contrast, the new MT data affirm previous interpretation about Tico anomaly located north of the study area being a shallow manifestation of relict alteration. MT data further delineated a NW-trending steep resistivity gradient northeast of the proposed energy support zone (ESZ). Faults along this gradient are good reinjection targets. |