Travertine stalactites (Ohio Caverns, western Ohio, USA) 10 : 無料・フリー素材/写真
Travertine stalactites (Ohio Caverns, western Ohio, USA) 10 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Ohio Caverns is the largest cave system in Ohio. It is located in a bedrock knob called Mt. Tabor on the southern side of the Bellefontaine Outlier (= Ohio's elevationally highest area). The cave is hosted in the Middle Devonian Columbus Limestone, which is part of a widespread shallow marine carbonate succession in eastern and midwestern America.The general term for all secondary mineral deposits occurring in caves is speleothem. Between 200 and 300 different minerals have been reported to occur in various speleothems around the world. The most common speleothem minerals are calcite (CaCO3), aragonite (CaCO3), and gypsum (CaSO4·2H2O). Calcitic speleothem is given the rock name travertine.Varieties of cave travertine are named based on morphology and origin. The most common type is dripstone, which includes stalactites, stalagmites, and columns. Other varieties include flowstone, knobstone (a.k.a. coralloids), helictites, shelfstone, rimstone, cave pearls, frostwork, etc.Shown above is a travertine stalactite, which is a variety of dripstone. Dripstone forms by precipitation of minerals (in this case, calcium carbonate - calcite) from dripping water. Dripstone structures attached to cave ceilings or upper walls are called stalactites. The corresponding structures on cave floors are called stalagmites.This is the largest stalactite at Ohio Caverns. It is just less than five feet long and is called the "Crystal King".The reddish-brown coloration on the cave wall is from iron oxide staining.Locality: Ohio Caverns, Mt. Tabor, east of the town of West Liberty, northern margin of Champaign County, western Ohio, USA----------------For a recent technical article on the geology of Ohio Caverns, see:scholarcommons.usf.edu/ijs/vol45/iss1/7/ |
| 撮影日 | 2016-10-23 10:19:52 |
| 撮影者 | James St. John |
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