Travertine dripstone (Shenandoah Caverns, Quicksburg, Virginia, USA) 10 : 無料・フリー素材/写真
Travertine dripstone (Shenandoah Caverns, Quicksburg, Virginia, 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 | Travertine dripstone in a cave in Virginia, USA."Cave formations" in caves are technically called speleothem. Most speleothem is composed of travertine, a crystalline-textured chemical sedimentary rock composed of calcite (CaCO3). Travertine forms in most caves and at some springs by precipitation of crystals from water. Pure travertine is white. The colors seen in the travertine shown above are from iron oxides. Travertine speleothem occurs in a wide variety of forms. The most common variety is dripstone, which forms by the action of dripping water. Downward-tapering dripstone structures attached to cave ceilings or upper walls are called stalactites. The corresponding structures on cave floors are called stalagmites. When grown together, they form columns.Shenandoah Caverns is developed in structurally tilted carbonates of the Conococheague Formation (Upper Cambrian). The tilted bedding is quite evidence in this photo.Locality: Shenandoah Caverns, Quicksburg, southern Shenandoah County, northern Virginia, USA |
| 撮影日 | 2016-05-13 10:10:16 |
| 撮影者 | James St. John |
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