Symmetrical ripple marks (Vinton Member, Logan Formation, Lower Mississippian; Dillon Reservoir railroad cut, Muskingum County, Ohio, USA) : 無料・フリー素材/写真
Symmetrical ripple marks (Vinton Member, Logan Formation, Lower Mississippian; Dillon Reservoir railroad cut, Muskingum County, 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 | Symmetrically-rippled, fine-grained quartzose sandstone in the Mississippian of Ohio, USA. (bedding plane view)Symmetrical ripples are moderately common sedimentary structures. In cross-section, when viewed perpendicular to the crests of the ripples, symmetrical ripple marks are more or less evenly shaped - they are symmetrical. Their presence in sedimentary rocks is diagnostic of deposition in a shallow water environment with a two-directional, back-and-forth (oscillatory) current. Symmetrical ripples marks are common in ancient shallow-water sandstone facies.The rock shown above is from the Vinton Member in eastern Ohio. The Vinton is the uppermost of four stratigraphic units in the Mississippian-aged, siliciclastics-dominated Logan Formation. Ascending from the base, they are the Berne Conglomerate Member, the Byer Sandstone Member, the Allensville Member, and the Vinton Member. The Vinton is dominated by sandstones, siltstones, and shales deposited in relatively shallow marine facies.The discoloration along the margin of this sample is a weathering rind.Stratigraphy: talus from the Vinton Member, upper Logan Formation, Osagean Series, upper Lower MississippianLocality: railroad cut 0.25 miles southeast of Every Road crossing, western side of northern Dillon Reservoir, ~between the towns of Toboso and Dillon Falls, western Muskingum County, eastern Ohio, USA (~40° 01’ 17.29” North latitude, ~82° 08’ 01.79” West longitude) |
| 撮影日 | 2017-08-27 14:29:57 |
| 撮影者 | James St. John |
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