The average growth rate is 0.13 mm a year
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.
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.
Stalagmites grow upwards from the floor of a cave due to the accumulation of mineral-rich water dripping from the ceiling. As the water drips and evaporates, it leaves behind mineral deposits like calcite which gradually build up over time, forming the stalagmite structure. This process can take thousands of years for a stalagmite to reach significant height.
It varies - from a few centuries to a few billion years. But its not a meteor until it hits an atmosphere (a matter of a few seconds to minutes).
Stalagmites and stalactites grow at an average rate of 0.005 to 0.01 inches per year. However, growth rates can vary depending on factors such as mineral content in the water, temperature, and cave conditions. It can take hundreds to thousands of years for them to reach a significant size.
Stalagmites and stalactites can take thousands of years to reach just a few inches. The rate of growth for a stalagmite is based on the amount of water that is flowing through the rocks and the amount of Ca dissolved in it, but they most certainly do not grow overnight. So, no, no human could stand still long enough to have a stalagmite form on them.
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.
Many Years. Many Years.
1 million years
1 million+ Years to be a diamonds... :/
1.
One Billion!
it takes a delta to form 100 years or more
There are many types of fossilization. Some take a surprisingly few number of years, and others occur over periods of millions of years.
It could take minutes or thousands of years, depending on the rate of cooling.
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.
Probably a few million years. Most likely many years, due to Evolution. :P