Monday, August 3, 2015

Travelogue Part 2: Mammoth Cave

 Mammoth cave is the longest cave in the world: possibly as long as 1000 miles, with 400 miles mapped so far.  But it's not laid out in a straight line.

The yellow on the map shows the crazy layout of the mapped part of the cave.  It was originally discovered as three different large caves before they realized it was all one cave!

The model at the bottom shows how the cave actually exists like a giant pile of spaghetti with many levels.  The model is just of the black box on the map.
 We started in the museum. 
 And then it was on to the cave!

 The cave was carved in soft sandstone and limestone by underground rivers.

Most of the cave system is covered by a layer of hard shale through which surface water can't pass.

This leads to a strange thing: most of the caves have no formations.  They are just smooth water carved sides and jagged rocks where ceilings caved in.

But in one part of the cave, the shale covering eroded allowing water from the surface to percolate through...



 The water dissolved the limestone and redeposited in stalactites, stalagmites, and all manner of beautiful cave formations!




2 comments:

Sue Elvis said...

Wendy,

We love cave exploring! We visited Jenolan caves at the beginning of the year. They're also limestone caves formed by an underground river. They have many, many spectacular formations because, unlike Mammoth cave, there is no waterproof shale layer.

The longest cave in the world? 400 mapped miles is a lot of cave! I wonder if more of the cave will be mapped. I was fascinated by the stories of the first explorers of our caves. They only had candles to see by, and, of course, no safety equipment, but they discovered so much. They spent every available hour underground following their passion. Later wealthy people would go on excursions to the caves, enjoying underground picnics, and there is even one cave where church services were held. Unfortunately, some of the formations were taken home as souvenirs. I bet Mammoth cave has its own similar stories.

It looks like you had a fantastic time at Mammoth cave. I wonder if your visit will spark off further cave learning adventures!

Wendy said...

I hope so, I love caves!

Mammoth cave has one large cavern with lots of small houses in it. People don't live there now, but they were used 100 years ago to try to cure tuberculosis.

They said that 5-10 miles more are mapped each year! They are using 3D scanning to map it now, but the first explorers were also candle lit and very brave! One of the best explorers was actually a slave who ended up giving tours of the cave, first as a slave and later as a freedman.

Great talking to you about caves!