Mudcracks (ABC Range Quartzite, Neoproterozoic; Pichi Richi Pass railroad cut, South Flinders Ranges, South Australia) 1 : 無料・フリー素材/写真
Mudcracks (ABC Range Quartzite, Neoproterozoic; Pichi Richi Pass railroad cut, South Flinders Ranges, South Australia) 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 | Mudcracks in the Precambrian of South Australia.Mudcracks are diagnostic sedimentary structures indicating subaerial exposure of sediment surfaces, with alternating wet & dry conditions. They are much more common that raindrop imprints, which indicate the same environmental setting. Mudcracks are most likely to occur in fine-grained siliciclastic rocks, fine-grained carbonate sediments, and in some evaporitic successions. Mudcracks are distinctive and easy to identify, but they do vary in appearance. The cracks themselves vary in width, depth, and areal density. Mudcrack polygons also vary in size & shape.The fantastic mudcracks seen here are on the base of a well-cemented quartzose sandstone bed - the original fine-grained unit in which the cracks were developed is now gone. The beds here have been tilted to near vertical by tectonic activity. The viewer is facing toward "stratigraphic up".Stratigraphy: ABC Range Quartzite, lower Ediacaran, upper NeoproterozoicLocality: Pichi Richi Pass railroad cut (eastern side of railroad), eastern side of Rt. 47, Pichi Richi Pass, southern part of the South Flinders Ranges, between the towns of Stirling North & Quorn, South Australia (32° 26' 18.29" South latitude, 137° 58' 40.28" East longitude) |
| 撮影日 | 2014-11-25 21:21:29 |
| 撮影者 | James St. John |
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