Cave formation begins when rainwater absorbs carbon dioxide as
it falls through the atmosphere. Rain water must have carbon
dioxide to become acidic. It must be acidic to chemically react to
the limestone bedrock. Rainwater is absorbed by the soil into the
ground. As rainwater comes through the soil it absorbs more carbon
dioxide that is being produced by plants that are dead. This
changes the ground water to a weaker form of CARBONIC ACID.
As it travels down through the ground it comes to solid rock.
When the rock is limestone or dolomite caves can form. The water
reacts chemically with limestone and slowly a larger and larger
space will form. This happens because the rocks are made of CALCIUM
CARBONATE.
This is what you call chemical erosion. As the space becomes
larger and larger the water can flow through. As it flows it erodes
. Physical erosion washes away rock and sand. This is what makes a
cave larger and forms an underground stream. Finally over hundreds
of thousands of years or even millions of years the cave is
formed.
To log this earth cache please undertake
the following tasks...
Answer these questions via email
:
- 1. What is the chemical formula for Carbonic
Acid?
- 2. What is the chemical formula for Calcium
Carbonate?
- 3. Erosion has caused the river to drop. Estimate the
height of the Dove Holes above the current river bed.
- 4. Estimate the diameter of both
holes.
And the your log on this page :
- You must post a photo of you and/or your GPS at Dove
Holes.
Feel free to log this earth cache as soon as you have undertaken
the tasks. Failure to perform the tasks will result in your log
being deleted (sorry!) I hope you enjoy this earth cache.