| Abstract |
Hydrothermal minerals of Hawaii can be grouped into five zones; (1) actinolite (>340°C). (2) chlorite (325-340°C), (3) montmorillonite (<325°C), (4) kaolinite, and (5) alunite. Actinolite, chlorite and monmorillonite zones are present in Hawaiian geothermal project well-A, Kilauea Volcano, Hawaii. A chlorite zone is also found in Koolau Caldera, Oahu. Kaolinite and alunite zones are present in southwestern Molokai. The zonal distribution of hydrothermal minerals is related to temperature, permeability, and composition of the hot fluid, and resulted from the vertical or lateral migration of the hot fluid to the surrounding basalts. |