How Fast Do Stalactites Grow?
For generations cave guides have been telling cave visitors that the stalagmites and stalactites that they see around them grow at incredibly low rates. The figure that is usually given is one inch per century for stalactites (they are the ones that hang down). That estimate, however, was not based on any scientific research. Even in the 1970s, the growth of these formations was not fully understood.
Now a group of scientists who believe in young Earth creationism has studied the chemistry of stalagmite and stalactite formation in actual cave conditions. They discovered that there are many variables in the growth of these formations. How much carbon dioxide dissolves in the water depends on temperature and pressure. The amount of carbon dioxide in the water can vary by a factor of five. The dissolved carbon dioxide turns the water acidic, causing it to dissolve calcium carbonate, that is, limestone. More turbulent water can dissolve more calcium carbonate. The same water under pressure can dissolve even more. Once the water seeps out of the cave ceiling, the pressure is relieved, the water evaporates, and the calcium carbonate begins to deposit to form the stalactite. Actual growth rates in actual caves have been observed as high as one inch every seven and a half days!
The violence and high pressures developed during the Genesis Flood would have provided the ideal conditions for producing a great deal of underground water supersaturated with calcium carbonate.