Stalagmite
From Wikipedia, the free encyclopedia
A stalagmite (from the Greek stalagma ("Σταλαγμίτης"), "drop" or "drip") is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate.
The corresponding formation on the ceiling of a cave is known as a stalactite. If these formations grow together, meeting in the middle, the result is known as a column.
There are various mnemonics to help remember which formation hangs from the ceiling (stalactite) and which rises from the floor (stalagmite):
- StalaCtite has a "c" for "ceiling".
- StalaGmite has a "g" for "ground".
- The T in StalacTite resembles one hanging from the ceiling, while the M in StalagMite resembles a formation rising from the floor.
- Stalactite is stretched "tite" (tight) by hanging from the ceiling.
- Stalactites have to hang on tight to the ceiling.
- Stalagmites might reach the ceiling.
- Stalagmite pushes up with all its "mite" (might) from the floor.
- "When the mites go up, the "tites" (tights) come down".
When touring caves with stalactites and stalagmites you might be requested to not touch the rock formations. This is generally because the formation is considered to still be 'alive' in that it is still growing and forming. Since the rock buildup is formed by minerals solidifying out of the water solution onto the old surface, skin oils can disturb where the mineral water will cling, thus affecting the rock formation.
Stalagmites can also form in lava tubes, although the mechanism of formation is much different. Stalactites and stalagmites can also form on concrete ceilings and floors, although they form much more rapidly there than in the natural cave environment.
