Interference rippled limestone (Fairview Formation, Upper Ordovician; Maysville West roadcut, Kentucky, USA) 1 : 無料・フリー素材/写真
Interference rippled limestone (Fairview Formation, Upper Ordovician; Maysville West roadcut, Kentucky, USA) 1 / 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 | Interference ripples & trace fossils in limestone in the Ordovician of Kentucky, USA. (camera lens cap for scale)This limestone surface is in the famous Cincinnatian Series of the tristate area of Ohio-Kentucky-Indiana. Rocks in the Cincinnatian were deposited in relatively shallow marine facies during the Late Ordovician. The Cincinnatian succession is mostly interbedded limestones and shales. Most of the limestones are event beds (= tempestites), deposited during ancient storms.The ridges seen here are interference ripples (a.k.a. “ladderback ripples”), which are uncommon sedimentary structures. They consist of sediment surfaces showing two sets of ripple crests intersecting at high angles. They indicate the existence of two successive or simultaneous current directions.The smaller-scale, irregularly-winding structures are trace fossils (burrows). Traces are any indirect evidence of ancient life. They include footprints, tracks, trails, burrows, borings, and bitemarks.Stratigraphy: Fairview Formation, lower Maysvillian Stage, middle Cincinnatian Series, Upper OrdovicianLocality: Jersey Ridge outcrop (= Harsha Bridge South outcrop; = Maysville West outcrop) - western side of Rt. 62/Rt. 68 roadcut through Jersey Ridge, just south of the Harsha Bridge over the Ohio River, northern Kentucky, USA (vicinity of 38° 40’ 28.48" North latitude, 83° 47' 52.42" West longitude) |
| 撮影日 | 2009-11-13 13:30:21 |
| 撮影者 | James St. John |
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