Tectonic Collision, Orogeny and Geothermal Resources in Taiwan

Abstract

The recent tectonic evolution of Taiwan created ideal conditions for geothermal resources: heat, water and permeability. We examine heat flow measurements, seismic tomography, seismicity, hot spring distribution, tectonic history, geology, and volcanism described in previous studies to understand the relation between tectonics and geothermal potential in Taiwan. Taiwan is the youngest tectonically created island on earth. The island formed as a result of the transition from subduction of the Eurasian Plate under the Philippine Sea plate to active collision. Collision results in orogenic mountain building. The geology of the island is primarily an accretionary prism from the historic subduction. This active orogeny creates unusually high geothermal gradients by exhumation of the warmer material from depth and by strain heating. As a result, temperatures reach up to ~200 degree C. Volcanoes in the northern tip of Taiwan provide an additional source of heat. Favorable fluid flow from meteoric waters and permeability from seismicity and faulting results in exploitable geothermal systems near the surface. These systems can potentially provide geothermal power generation throughout the whole island, although there are currently only two geothermal power plants in Taiwan.