| Title | Hydro-geophysical Model of the Southern Negros Geothermal Project, Central Philippines Based on Magnetotellurics Resistivity |
|---|---|
| Authors | Rhoel Enrico R. Olivar, Nilo A. Apuada |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | magnetotellurics resistivity, Southern Negros Geothermal Project |
| Abstract | A geophysical investigation using magnetotellurics (MT) resistivity was conducted over the Southern Negros Geothermal Project in central Philippines. A 1-D layered resistivity modeling of the MT data resulted to the delineation of two high-resistivity anomalies (>50 - 100 -m) overlain by a zone of low resistivity ( 10 -m). One anomaly centers beneath Lagunao Dome, and defines the upflow center of the Southern Negros Geothermal Production Field in Palinpinon. A smaller anomaly on the other hand was delineated beneath Mt. Talines and Cuernos de Negros and is thought to describe a separate geothermal system, referred to as the Dauin prospect. The high-resistivity anomalies are associated with the presence of high temperature but low conductivity mineral alteration products such as illite, epidote, chlorite, etc. that dominate most geothermal systems. The low-resistivity ( 10 -m) layer in turn is associated with clay hydrothermal alterations like smectite and illite-smectite normally occurring at regimes of intermediate temperatures (~70?C). |