Photo by Jennifer Boyer: Geothermal Greenhouses in Hveragerði, Iceland. Geothermal Greenhouses: A...
Basalt
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.
Geothermal Glossary
Word of the Week – Felsic
Felsic A geological term referring to igneous rocks that are equivalent to rhyolite and granite in composition.
Word of the Week – Flowback
Flowback Return flow of slickwater that was injected during a stimulation. This is a highly controlled process in which well head pressure is reduced to allow managed fluid recovery. Fluids are commonly sampled and chemically analyzed to determine the effects of...
Word of the Week – Fumarole
Fumarole A steam vent and surface thermal feature that is commonly associated with steaming ground and mud pots in hydrothermally and volcanically active areas.