Interference ripples in quartzose sandstone (Berea Sandstone, Upper Devonian or Lower Mississippian; Ohio, USA) : 無料・フリー素材/写真
Interference ripples in quartzose sandstone (Berea Sandstone, Upper Devonian or Lower Mississippian; Ohio, 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 | Interference ripples in quartzose sandstone from the Paleozoic of Ohio, USA. (public display, Orton Geology Museum, Ohio State University, Columbus, Ohio, USA)Interference ripples (a.k.a. “ladderback ripples”) 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 two successive current directions indicated by the ripples on this slab are left-to-right and up-and-down. The ripple set with ridges oriented up & down formed by a dominant shallow-water, two-directional current moving perpendicular to the ridge crests (= left-and-right direction, when looking at this upright slab).The ripple set with ridges oriented left & right formed by a subordinate shallow-water, two-directional current moving perpendicular to their ridge crests (= up-and-down direction, when looking at this upright slab).Stratigraphy: Berea Sandstone, uppermost Famennian Stage to lowermost Kinderhookian Stage, uppermost Upper Devonian to lowermost Lower MississippianLocality: unrecorded/undisclosed site in Ohio, USA |
| 撮影日 | 2007-08-13 15:08:30 |
| 撮影者 | James St. John |
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