Vertical shaft (Sidesaddle Pit, Black Snake Avenue, Mammoth Cave, Kentucky, USA) 4 : 無料・フリー素材/写真
Vertical shaft (Sidesaddle Pit, Black Snake Avenue, Mammoth Cave, Kentucky, USA) 4 / 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 | Western Kentucky's Mammoth Cave is the longest cave system on Earth, with 426 miles known and mapped as of fall 2022. The name does not refer to the early discovery of fossil mastodon or mammoth bones here. Rather, the name refers to the immense size of many rooms and passages.The system has a variety of cave passages: tubular passages, canyon passages, vertical shafts (domepits), keyhole passages, and giant canyon passages.Sidesaddle Pit is a moderately large vertical shaft that can be viewed during the 2-hour, 2 mile-long Historic Tour. Vertical shafts, also called domepits, are large, silo-shaped, dissolutional features in caves. They form in the vadose zone (above the water table) as downward-moving groundwater dissolves limestone by enlarging joints or joint intersections.Limestones of the Fredonia Member line the walls of Sidesaddle Pit. The Fredonia is one of many members in the Ste. Genevieve Limestone (upper Middle Mississippian). Vertical grooves called flutes are incised on the walls here. Flutes are vadose dissolutional features on vertical cave walls. Similar to flutes are rills, which are vadose dissolutional features on sloped limestone surfacesThe rubble-covered floor of this domepit appears to bottom out in the lower Ste. Genevieve Limestone (Fredonia Member) or the upper St. Louis Limestone.Locality: Sidesaddle Pit, Black Snake Avenue, Mammoth Cave, west-central Kentucky, USA |
| 撮影日 | 2019-03-16 15:06:36 |
| 撮影者 | James St. John |
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