The Fluid Inclusion Study of Core in the Ilan Plain Geothermal System, Taiwan

Abstract

The Ilan Plain, is located in the Northeastern Taiwan where is heavily influenced by the opening of the Rykyu trough and resulted in thermal anomaly. The origin this anomaly is currently debating. Fluid inclusion samples, taken from 700m to 900m from the total 1500m the core of HongTsaiLing well of Ilan Plain. The preliminary results showed that most veins are composed of quartz and calcite and formed along cleavage. It is rare to find quartz only veins. Quartz and calcite are commonly mosaic deposited and some recrystallization found for quartz. The homogenized temperatures (Th) by quartz for HongTsaiLing is 220℃ ~272℃ and the melting temperature (Tm) is -3℃~-2.7℃, while the The homogenized temperatures (Th) by calcite is 170℃ ~210℃ and the melting temperature (Tm) is -4.7℃~-2.2℃。