Travertine speleothem (Carlsbad Caverns, New Mexico, USA) : 無料・フリー素材/写真
Travertine speleothem (Carlsbad Caverns, New Mexico, USA) / 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 | Carlsbad Caverns is developed in Permian reefal limestones, principally the Capitan Limestone. The cave was dissolved out from the bottom-up by sulfuric acid (H2SO4), formed by the oxidation of H2S gas near the top of the paleo-water table. The H2S gas was likely derived from nearby petroleum fields. Available evidence indicates that Carlsbad Caverns started forming in the Late Permian, not long after deposition of the original reef sediments. However, most of the cave system was dissolved out during the Tertiary.The walls, ceilings, and floors of much of Carlsbad Caverns are richly decorated with speleothem ("cave formations"). Carlsbad speleothem is principally composed of travertine (calcitic speleothem - CaCO3) and gypsum (CaSO4·2H2O). The travertine speleothem shown above is dripstone, formed by dripping water. Stalactites have fused with stalagmites, forming columns. The lower portions of these columns are covered with flowstone, formed by films of flowing water. |
| 撮影日 | 2014-11-22 19:23:59 |
| 撮影者 | James St. John |
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