Identifying Potential Geothermal Area Beneath Thick Alluvium Sediments of Ilan Plain, Taiwan by Clay Mineral Assemblages and Petrography

Abstract

The study area, Ilan Plain of Taiwan, is covered by Holocene alluvium sediments, ranging from 100 to 1200 meters. This study collected samples from four boreholes, the SanXin-BH01 (602m), JeiYuan-BH01 (1438m), HTL01 (2200m) and HTL02 (2800m), under the project of Taiwan National Energy Program-Phase II. JeiYuan-BH01, HTL01 and HTL02, mainly consist of slate, meta-sandstone, and meta-sandstone with cleavages, while SanXin-BH01 that only consists of slate. Illite, kaolinite, and chlorite are found in all samples c. The montmorillonite, however, exists in SanXin-BH01, JeiYuan-BH01, and HTL02 except HTL01. According to the results of previous studies, the montmorillonite may serve as an indication of geothermal potential area particularly in the low-grade metamorphic rock. With it we have identify the existence of geothermal potential in the area of SanXin-BH01, JeiYuan-BH01, and HTL02.