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Eriboll Group
The Ardvreck Group is a Group (stratigraphy), stratigraphic group of early Cambrian age found in the Northwest Highlands of Scotland. It lies unconformity, unconformably on gneisses of the Lewisian complex or sandstones of the Torridon Group. It consists of two formations, the basal quartzites and quartz arenites of the Eriboll formation and the overlying dolomitic siltstones and sandstones and quartz arenites of the An-t-Sron formation. It is overlain conformably by the Ghrudaidh formation of the Durness Group. The Ardvreck Group was at one time known as the "Eriboll Group". References {{Reflist Geological groups of the United Kingdom Geology of Scotland Cambrian Quartzite groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skolithos
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow with a distinct lining. It was produced globally by a variety of organisms, mostly in shallow marine environments, and appears as linear features in sedimentary rocks. Depositional environments ''Skolithos'' ranges in age from early Cambrian to the present and is found throughout the world. They occur in sediments and sedimentary rocks, primarily sands and sandstones. They are typically marine in origin, and are commonly associated with high-energy environments close to the shoreline. They have also been reported from freshwater lacustrine settings, but have rarely been described from carbonate rocks. Vertical ''Skolithos'' can also occur in alluvial sediments such as braided river deposits, where the periodic fluctuation of water is an important factor in the formation of this structure. This periodic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
