Dark grey fine grained volcanic rock composed of plagioclase, pyroxene and olivine, with relatively low silica (45-52 wt %). The composition reflects an upper mantle origin. Basalt is the most common type of volcanic rock on Earth, and it erupts from mid-ocean spreading ridges and hot spots (e.g., Hawaii and Iceland). The intrusive coarsely crystalline igneous rock equivalent is called gabbro.
Binary Cycle Power Plant A power plant in which the produced geothermal fluid passes through a heat exchanger and heats a low boiling point liquid, commonly an organic compound such as pentane, to vaporize and condense as it passes through a turbine and generate...
Breccia Angular to sub-angular fragments of broken rock that are cemented together that are highly permeable and form on the surface due to sedimentary or igneous processes or in fault zones.
Brine In producing geothermal fields, this term refers to the hot water that is produced from wells. It is rarely as salty as implied. Instead, the salinities of most natural hot waters are commonly less than seawater, but they contain a wide range of rock-forming...
