_svg.png){kind=link}
The Witch's Finger in the Carlsbad Caverns
A stalagmite (UK: /ˈstæləɡmaɪt/, US: /stəˈlæɡmaɪt/; from the Greek Σταλαγμίτης stalagmitês), "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. This stalagmite formation occurs only under certain pH conditions within the underground cavern.[1] The corresponding formation on the ceiling of a cave is known as a stalactite. If these formations grow together, the result is known as a column.
The Hall of Giants in the Carlsbad Caverns
Stalagmites should normally not be touched, since the rock buildup is formed by minerals precipitating out of the water solution onto the old surface; skin oils can alter the surface where the mineral water will cling, thus affecting the growth of the formation. Oils and dirt from human contact can also stain the formation and change its colour permanently.
Similar structures can also form in lava tubes, known as lavacicles, although the mechanism of formation is very 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.
The largest stalagmite in the world is 62.2 metres (220 feet) high and is located in the cave of Cueva Martin Infierno, Cuba.[2]
Stalagmite art[]
Trekking the Zagros Mountains of south Iran, approximately 6 km from the ancient city of Bishapur, one may yet have the luck to find Shapur cave (Persian: غار شاپور) wherein rises, on the fourth of five terraces, the colossal 3rd-c. CE statue of Shapur I, second ruler of the Sassanid Empire. The statue, carved from one stalagmite, is nearly seven meters high.
References[]
- ↑ C. Michael Hogan. 2010. Calcium. eds. A.Jorgensen, C. Cleveland. Encyclopedia of Earth. National Council for Science and the Environment.
- ↑ Fothergill, A. et al. (2006) Planet Earth, London, BBC Books, pages 184-185