Apparent hardground (probably from the Waldron Shale, Middle Silurian; St. Paul Stone Quarry, St. Paul, Indiana, USA) 1 : 無料・フリー素材/写真
Apparent hardground (probably from the Waldron Shale, Middle Silurian; St. Paul Stone Quarry, St. Paul, Indiana, 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 | Apparent hardground in the Silurian of Indiana, USA. (geology hammer for scale)The St. Paul Stone Quarry in St. Paul, Indiana, USA has four Middle Paleozoic stratigraphic units exposed along the walls:Geneva Dolomite Member of the Jeffersonville Limestone (Lower Devonian)---------------------------------------------Louisville Limestone (Middle Silurian)---------------------------------------------Waldron Shale (Middle Silurian)---------------------------------------------Laurel Member of the Salamonie Dolomite (Middle Silurian)The rock shown above is a loose quarry block that probably derives from the Middle Silurian Waldron Shale. Its upper surface is somewhat smoothly sculpted - the classic appearance of a hardground. Hardgrounds are synsedimentarily cemented seafloors. Encrusting fossil organisms and borings are often found on hardground surfaces. This sample appears to be lacking a fossil hardground biota.Stratigraphy: Waldron Shale, upper Niagaran Series (upper Wenlockian), Middle SilurianLocality: St. Paul Stone Quarry, 1 mile northwest of the town of St. Paul & 1.75 miles southeast of the town of Waldron, southeastern Shelby County, southeast-central Indiana, USA (39° 26' 09.22" North, 85° 38' 38.66" West) |
| 撮影日 | 2015-10-03 08:57:56 |
| 撮影者 | James St. John |
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