Fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 11 : 無料・フリー素材/写真
Fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 11 / 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 | Coral in fossiliferous limestone in the Devonian of Ohio, USA.The Columbus Limestone is a significant carbonate unit in the Devonian of central and northern Ohio. It's actually part of a much more widespread sheet of Devonian carbonates that extends from New York State to the Midwest. The Columbus Limestone represents deposition in a subtropical, shallow-water, carbonate platform environment. The rocks are principally micritic limestones, fossiliferous wackestones, and fossiliferous packstones. Some chert nodules are present in the unit. Fossils are typical Paleozoic shallow marine invertebrates - favositid corals, rugose corals, stromatoporoids brachiopods, crinoids, blastoids, bryozoans, trilobites, bivalves, gastropods, cephalopods, rostroconchs, and tentaculites. Microfossils include conodonts and charophyte oogonia. Other fossils in the Columbus Limestone include vertebrates (fish), land plants (rare), and trace fossils. Some fossil horizons in the Columbus Limestone are partially silicified.The thick-bedded Columbus Limestone is overlain by the thin-bedded Delaware Limestone. The contact is a prominent disconformity (a type II sequence boundary). Biostratigraphic studies have shown that one conodont biozone is missing at the Columbus-Delaware contact in central Ohio, probably representing ~1 to 3 million years. The base of the Columbus Limestone is a major, continent-wide unconformity representing the Tippecanoe-Kaskaskia megasequence boundary (a type I sequence boundary).The broken fossil seen here is a solitary rugose coral, seen in transverse cross-section. It has been mostly silicified - the original calcareous skeleton has been replaced by quartz (SiO2).Classification: Animalia, Cnidaria, Anthozoa, RugosaStratigraphy: upper Columbus Limestone, Eifelian Stage, lower Middle DevonianLocality: roadcut along the southern side of Emerald Parkway, immediately east of Rt. 257 intersection, Dublin, northwestern Franklin County, central Ohio, USA (40° 06' 34.79" North latitude; 83° 06' 35.73" West longitude)-------------------------------See info. at:en.wikipedia.org/wiki/Rugosa |
| 撮影日 | 2018-04-08 15:51:45 |
| 撮影者 | James St. John |
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