A solutional cave , solution cave , or karst cave is a cave usually formed in the soluble rock limestone . It is the most frequently occurring type of cave. It can also form in other rocks , including chalk , dolomite , marble , salt beds , and gypsum .
6-410: The Te Ana-au caves are a culturally and ecologically important system of limestone caves on the western shore of Lake Te Anau , in the southwest of New Zealand . They were re-discovered in 1948 by Lawson Burrows, who found the upper entry after three years of searching, following clues in old Māori legends . It later became a major tourist attraction for the area, as the part of the caverns close to
12-745: Is dissolved by natural acid in groundwater that seeps through bedding planes , faults , joints , and the like. Over geological epochs, these openings expand as the walls are dissolved to become caves or cave systems. The portions of a solutional cave that are below the water table or the local level of the groundwater are flooded. The largest and most abundant solutional caves are located in limestone. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. These include flowstones , stalactites , stalagmites , helictites , soda straws , calcite rafts , and columns . These secondary mineral deposits in caves are called " speleothems ". Limestone dissolves under
18-754: The action of rainwater and groundwater charged with H 2 CO 3 ( carbonic acid ) and naturally occurring organic acids . The dissolution process produces a distinctive landform known as " karst ", characterized by sinkholes and underground drainage. Solutional caves in this landform—topography are often called karst caves. Lechuguilla Cave in New Mexico and nearby Carlsbad Caverns are now believed to be examples of another type of solutional cave. They were formed by H 2 S ( hydrogen sulfide ) gas rising from below, where reservoirs of petroleum give off sulfurous fumes. This gas mixes with ground water and forms H 2 SO 4 ( sulfuric acid ). The acid then dissolves
24-476: The caves lie in the Murchison Mountains (where the endangered South Island takahē were rediscovered), and are themselves very fragile, access is restricted. Commercial guided tours by punt through the water-filled caverns run daily, operated by RealNZ. 45°17′43″S 167°43′37″E / 45.2954°S 167.727°E / -45.2954; 167.727 Limestone cave Bedrock
30-400: The lake shore is home to glowworms . The unofficial name used by the national caving association is Aurora . The caves are geologically young (estimated 12,000 years) and hence there is only one tiny stalactite. The Māori name Te Ana-au can be translated as "The Swirling Cave" ( te : the; ana : cave; au : swirling) in reference to the water running through it. The water, Tunnel Burn, is
36-471: The outflow of Lake Orbell . Lawson Burrows and his business partner Wilson Campbell set up Fiordland Travels as a tourism company for their venture. In 1965, they sold their company to Olive and Les Hutchins , who had been in the tourism business in Fiordland since 1954. The Hutchins took over the company name but rebranded in 2002 to Real Journeys. The company rebranded again to RealNZ in 2022. Since
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