Can you clarify the statement: "stalagmites grow rather slowly.00028.037 in/yr (0.007.929 mm/yr)" as I think there may be a typo here please?
Also is there any online references for this other than "World of Earth Science" please?
I agree, there is a typo there; I will send that to the editing department to be fixed.
Stalagmites are mineral deposits that grow up from cave floors. Their name derives from the Greek word for "dripping", which is an apt description of how they form. When water laden with dissolved minerals keeps trickling or dripping on the same spot, the minerals are deposited in a formation that slowly build up into a pillar-shaped formation.
The growth rate of any specific stalagmite varies, depending on the drip rate, the concentration of dissolved minerals in the water, and the evaporation rate inside the cave, which is determined by the temperature and humidity of the cave. So, while we can expect the rate of stalagmite growth to be consistent from stalagmite to stalagmite within a single cave, the rate can vary quite considerably from one cave to another; in some areas the rate also changes seasonally.
According to this study, the actual rate of growth of stalagmites seems to be in the range of about 0.1 mm/year to about 1.2 mm/year.