Archaeocyathan limestone (Wirrapowie Limestone, Lower Cambrian; Mernmerna railroad bridge dry creek cut, South Australia) 2 : 無料・フリー素材/写真
Archaeocyathan limestone (Wirrapowie Limestone, Lower Cambrian; Mernmerna railroad bridge dry creek cut, South Australia) 2 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Fossiliferous limestone in the Cambrian of South Australia.The limestone seen here has archaeocyathans (click on the photo once or twice to zoom in), formerly a mystery group of sessile, benthic, filter-feeding organisms (Phylum Archaeocyatha), but now known to be an extinct group of sponges (Phylum Porifera). Archaeocyathans are only known from Lower Cambrian rocks - the classic localities on Earth for these fossils are Siberia and Australia.This is part of a South Australian Lower Cambrian unit called the Wirrapowie Limestone, which consists of a limestone succession having archaeocyathans, trilobites, stromatolites, shell hash horizons, limestone conglomerates/intraclastic limestone breccias, and oncolitic limestones.Stratigraphy: Wirrapowie Limestone, Tommotian Stage to lower Atdabanian Stage, lower Lower CambrianLocality of section: dry creek cut upstream from an abandoned railroad bridge at Mernmerna, South Australia (31° 34’ 25.30" South latitude, 138° 24’ 44.77" East longitude) |
| 撮影日 | 2006-08-18 20:40:56 |
| 撮影者 | James St. John |
| タグ | |
| 撮影地 |