The Kartchner Caverns are located south east of Tucson with a series of tunnels and passageways 2.4 miles long . The caverns are made out of limestone and are filled with many speleothems (cave deposits) such as stalactites and stalagmites that have been growing for over fifty thousand years and continue to grow today.Two caves of particular interest within the Kartchner Caverns are the ‘Throne Room’ and the ‘Big Rooms.’ The Throne Room is home to one of the worlds largest soda straws (thin cylindrical stalactites), over 21 feet high.The Big Room tour is only open Mid–October to Mid-April due to being used as a nursery roost for cave bats in the summer. The Big Room is home to the worlds most extensive formation of brushite moonmilk (limestone precipitate) and other rare for-mations first found in these caves.

 

The Kartchner Caverns were first discovered in 1974 by cave explorers Randy Tufts and Gary Tenen who were investigating a sinkhole near the Whetstone Mountains. Upon inspecting the sinkhole they found a passageway, just around 10 inches in width that had a faint air current , suggesting a larger cave was located deeper within. After crawling though the tiny passages for hours having to stop to use a sledgehammer to open up part of the passageway, they eventually got to a passage large enough to stand up in. As they continued into a larger room the air got damp-er and warmer, and there were many more speleothems bright orange in colour. It was clear they had made a remarkable discovery, just half a mile from the highway.To prevent vandalism of the caverns the two kept it quiet for four years until they realized it would take a lot more than the two of them to protect it. After informing the land-owners after which the caverns are named they began negoti-ations with State Parks to buy the area. State Parks successfully acquired the property in 1988 and after 10 years of construction were able to open the top caverns in 1999 and the lower caverns in 2003.

 

There are many types of speleothems that occur in the Kartchner Caverns some of them are even unique to them. They all occur due to water degassing when it leaves the limestone rock and cannot hold onto any minerals it has picked up, these minerals are deposited and form different Speleothems depending on their location. Stalagmites: Are the result of water dripping from the cave ceiling onto the floor. The minerals deposited there gradually accumulate to form spike-like structures made out of calcium carbonate. Stalactites: Are the opposite of Stalagmites and form on the ceiling of the caverns, they also form when water drips from the ceiling; from the calcium carbonate precipitate that is left behind on the ceiling. Water will then drip down this precipitate that keeps growing as more is left behind as the water falls to the ground. When stalag-mites and stalactites join together they are referred to as columns.Turnip Shields: First discovery of this feature was in the Kartchner Caverns. As the name suggests, these are turnip shaped speleothems that hang from the ceilings of the cavernsBrushite Moonmilk: One of the worlds largest formation is found in the Big Room. Usually found as a calcite the form found in the Kartchner Caverns is pasty due to mixing with bat guano. Flowstone: Occurs when water flows down the walls of the cave, gradually a solution of calcite forms a sheet over the wall and has a spongy texture.

 

This information is courtesy of Nick Webley, University of South Wales.