Did you know .... Europe's largest banana producer is not who you think? One of the northernmost...

Helium gas is a trace constituent of groundwater and thermal fluids, and the ratio of 3He to 4He can be measured with a high-precision mass spectrometer to determine whether it is derived from air, from the radioactive decay of uranium and thorium in the crust, or from the mantle. The latter is a characteristic feature of volcanic and geothermal gases.
Geyser A rare type of hot spring that periodically discharges a fountain of hot water and steam (or sometimes just gas).
Gneiss Metamorphic rock that forms under intense pressure and high temperature and that is made of quartz, feldspar, amphibole and mica. Gneiss represents the highest grade of metamorphic rock, which is characterized by alternating bands of dark and light-colored...
Granite Light colored, coarse grained, intrusive rock with a felsic (silica-rich) composition that is mostly made of quartz, sodium and potassium-bearing feldspar, and plagioclase. Minor amounts of other minerals can include mica (muscovite, biotite), hornblende,...