A very good question! There was an old study that reckoned on "one inch per 1000 years" but whilst that may have applied to one particular study, and probably fair for caves in temperate regions it is by no means universal.
No, it is stalactites that form on the ceilings. Stalagmites form on the cavern floors.
Stalagmites form when water from the stalactite drips down water and that water has minerals in it
When stalactites and stalagmites join it is called a column
Stalac"tites", top, or on the roof of the cave. Stalagmites form on the floor of caves.
rain
No, it is stalactites that form on the ceilings. Stalagmites form on the cavern floors.
Stalagmites form when water from the stalactite drips down water and that water has minerals in it
Calcium Carbonate
When stalactites and stalagmites join it is called a column
Stalac"tites", top, or on the roof of the cave. Stalagmites form on the floor of caves.
rain
No, they form on the ground. Stalactites form on the ceiling.
Stalagmites
They are stalagmites.
The opposite would be stalactites, which form from the ceiling down, while stalagmites form from the floor up. (The venerable mnemonic is that stalactites hold tite/tight to the ceiling.)
In the basement of the Lincoln Memorial in Washington, D.C. are examples of stalactites and stalagmites. The memorial was built in 1922. Rainwater seeping through the marble floor has formed stalactites up to five feet long in just 40 years. A picture was taken in the 1960's. There are many other examples of stalactites, stalagmites and flow cones forming rapidly under buildings recently created.
Which ones? Oh, and "stalactites". They form in caves developed in limestone.