| Title | Constructing geothermal conceptual model of Huangzui volcano, Northern Taiwan |
|---|---|
| Authors | T. Song, S. Song, Y. Lu, H. Hase, T. Lin, P. Lin |
| Year | 2024 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Tatun, Geothermal, conceptual model |
| Abstract | The Huangzui volcano, situated within the Northern Tatun Volcano Group (TVG), stands as a focal point for geothermal exploration and development in Taiwan. From the 1970s to the 1980s, Taiwan CPC and the Industrial Technology Research Institute (ITRI) undertook extensive drilling campaigns, resulting in over 10 exploration wells being drilled in the region, with the deepest well reaching a depth of 2025 meters and encountering a maximum temperature of 160°C. Recently, a 1MW geothermal power plant utilizing shallow steam pockets to generate electricity was constructed in this region, marking the first geothermal power plant built in a volcanic region of Taiwan. The magnetotelluric data, combined with geochemical analyses and drilling results, reveal that at the northern side of the Huangzui volcano's hydrothermal products in the volcanic formations are predominantly characterized by smectite and kaolinite at greater depths. Transitioning into the sedimentary basement, an alunite zone predominates, alongside ore-forming minerals such as enargite and zunyite, indicating a high acidity and high sulphidation epithermal environment, with an intrusive dike occurring at a depth of 1,000 meters. The central lava flow acts as a lateral barrier to fluid flow, while the fracture system in this region exhibits high-angle dips. As a result, temperature profiles of exploration wells away from the geothermal manifestation indicates conductive heat transfer rather than convection due to lack of fluid circulation. Subsequently, the infiltration of meteoric water into the volcanic fluid results in the production of immature, steam-heated waters sourced from a shallow low-pressure steam reservoir at 0 to 200 meters asl. |