The Caves
These are relatively young caves formed 50-100 thousand years ago. Unlike the majority of rock in the area the caves are not volcanic but made of limestone and were once part of the sea bed. Over time the caves have been carved out by the Okupata Stream. Evidence of their oceanic origin can be seen in places where the stream has washed the limestone and exposed small shells.
In several areas of the caves small stalactites are starting to form. Stalactites are calcium carbonate deposits. Water (containing carbon dioxide) dissolves calcium carbonate rock forming a calcium bicarbonate solution. This solution travels through the rock until it reaches an edge and if this is on the roof of a cave, drips down. When this solution comes into contact with air the chemical reaction that created it is reversed and particles of calcium carbonate are deposited.
In the stream bed at the entrance to the caves and in the caves themselves a variety of volcanic rocks can also be seen. These rocks were formed further upstream and are simply washed down during flood times and into the caves.
The Earth Cache
To complete this earth cache please email me the answers to the following questions (include your username and the name of this cache). Please do not post answers in your log. You may log your find as soon as you have emailed the answers to me i.e. you do not need to wait for permission. I will be checking logs and email you if there is a problem. Please no cheating it just spoils it!
Question 1. Above the main cave entrance there is a very large rock. Estimate the width of this rock? Describe it's appearance (colour/texture) and what type of rock you think it is?
Question 2. On the day of your visit how deep is the water at the cave entrance (take the reading on the depth gauge there)? What do you think will effect the depth of this water?
Question 3. Stand at the entrance to the main cave and shine your light up in front of you onto the ceiling of the cave. There is a deposit there. Describe the colour of this deposit and what you think it is?
Optional. Try to find and identify different rock types in the area near the caves, take a picture and post this with your log.
You DO NOT need to enter the caves to complete this earth cache. Only enter the caves with people who know them well as this is a cave network and it is easy to get lost. Heavy rainfall may result in rising water levels in the caves, which may cause them to flood.
Please enjoy and respect the area. Happy Earth Caching!