| Abstract |
The occurrences of each may be controlled by lithology, temperature, pressure, fluid composition or any combination of these. Minerals may reflect current conditions (mineral at equilibrium), or previous condition (metastable minerals), or they may reflect transition or intermediate phases as the mineralogy adjusts to a new temperature, pressure, compositional environment (unstable, transient mineralmineral assemblages in Lahendong drillholes can be divided into 3 groups : epidote-chlorite and sericite-actinolite group. Each mineral group was formed under somewhat varying physical chemical conditions, the implication from these upon the mineral filling this geothermal history . |