When traveling over the Nullarbor Plain its easy to become bored with the seemingly endless landscape. I know. I've done it. But its interesting to know what lies on top masks the wonders beneath.
From fellow geocacher ReticBob: "Edmund Alexander Delisser ... named the Nullarbor in 1865. He never married or had any if his own children to claim his name to fame. Edmund died north of Cairns in 1900."
Nullarbor Plain is the world's largest single piece of limestone and covers around 200,000 square kilometres. When limestone interacts with underground water it dissolves to form a 'karst' landscape - an amalgamation of caves, underground channels and a rough, bumpy ground surface.
The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, or bedding planes. As the bedrock (like limestone or dolostone) continues to break down, its cracks tend to get bigger. As time goes on, these fractures will become wider, and eventually, a drainage system of some sort may start to form underneath. If this underground drainage system does form, it will speed up the development of karst arrangements there. This increase in rate of karst feature development will be due to the fact that more water will be able to flow through the region.
The Nullarbor Plain hides much of its beauty. Beneath the surface of this huge park is a vast cave system, much of it unexplored. Passages run for kilometres, linking huge underground caverns. Some contain saline ground water. Others have interconnecting passages that form extensive underwater labyrinths.
To verify your find of this cache you need to answer the following questions.
1. What word is "karst" based on, and what is the definition of that word?
2. What type of holes form on the surface when karst collapses? Name one that is nearby to this area.
3. Look at the ground and rock you see. What colours are visible in the rock?
Send your answers to me via Geocache email messaging. You can log your find straight away, but please understand logs will be removed if no email is received or answers incorrect/guessed.
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