Mammoth Cave NP, Kentucky 2016
Becky, (my wife), and I drove the Kentucky on October 20th, 2016 to explore Mammoth Cave National Park.
Despite its many underground marvels, the most impressive feature of Mammoth Cave is its over-whelming size.
Nearly 200 miles of passageway have been surveyed. Like most limestone caverns, the labyrinth that makes up Mammoth Cave was formed by water.
Between 200 and 600 million years ago a shallow sea covered much of the continent, and seashells and oceanic ooze settled to the bottom, where they gradually hardened to form a thick deposit of limestone. Sand, silt, and clay were cemented into a protective overlying layer of sandstone and shale. This giant roof of shale and sandstone form the upper cap of the cave system in Mammoth Cave. This rocky layer acts as an umbrella, preventing the slow dripping of water into the cave. It is the action of water that forms stalactites and stalagmites. Without the water, you don’t get these formations.
Slightly acidic groundwater eventually dissolved openings in the limestone, (Mammoth Cave) after it had been uplifted above sea level.
Ten million years ago, rainwater infiltrated the soil, becoming a weak carbonic acid, and slowly began dissolving the limestone. By a million years ago, that rainy trickle had become a network of underground rivers and streams carving vast and interconnected tunnels. To date, the cave has at least five levels, extending up to 122 m below the surface. The older, upper streams drained and dried as newer, younger channels formed beneath them, as still continues today at places like Echo River.
Dissolved minerals released from water seeping into the cave have created many fantastically shaped formations, which include some, resembling needles, pendants, flowers, and coils. (Pictured below)
However, Mammoth Cave contains mostly of a long series of subterranean rooms and passageways. They twist and turn like strands of spaghetti, waving their way through the Earth’s crust. Some rooms are enormous and some passageways are just large enough for a small person to squeeze through.
Our main reason to visit Mammoth Cave comes in exploring the many passageways and seeing the sheer size of the rooms.