Cave pillar
Also called: Column · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
A cave pillar is a column of calcium carbonate that joins the roof and floor of a limestone cave. Water dripping through the roof loses carbon dioxide or evaporates. It then leaves behind tiny amounts of calcium carbonate. A stalactite slowly grows down from the roof, and a stalagmite grows up from the floor. A pillar forms when the two meet and fuse. Pillars vary in thickness and take a very long time to form. Another name for a cave pillar is a column.
Example
Borra Caves in Visakhapatnam district, Andhra Pradesh, have stalactites, stalagmites and pillars formed in limestone.
Don't confuse with
- Stalactite and stalagmite: a stalactite hangs from the roof and a stalagmite rises from the floor. A pillar forms only when they join. Memory aid: a stalactite holds "tight" to the ceiling.