Complex 3-D Geological Model Construction for Volcanic Geothermal Area in North Taiwan

Abstract

This paper describes the 3-D geological concept model as a construction tool (GeoModelBuilder-3D), developed by the author. This tool is then used to build the conceptual model from a candidate geothermal site around the Tatun Volcanic Group (TVO) and Huang-Zuei Volcano (HZV). With the established preliminary models, the geothermal heat source model thereby can be effectively evaluated at two different local scales, including the large model (TVO area) and small model (HZV site) respectively. For engineering application, they can serve as a good tool for engineering management of the thermal reservoirs and reach sustainable operation. Prior to commercial power generation, current results of model studies should be regarded as the initial guess. Subsequent modifications are taken for granted to cope with new additional geological data, including new finding on supplementary drilling, geophysical survey, geochemical analysis, etc. According to the current conceptual model assessment on HZV site, the geothermal heat source model at north HZV should be the residual heat flow of later stage magma activity of TVO. The high steam content heat flow derived from deep seated magma chamber at HZV, which went through some Neo-tectonic structures near crater, and finally migrated into shallow ground surface. There are many obvious volcanic heat signatures and geothermal manifestations in the surrounding area, including many hot springs, fumaroles, and widely distributed areas of metasomatism. All of these constituted an excellent geothermal site for engineering development.