| 词条 | Eday Group |
| 释义 |
| name = Eday Group | image = Red Head on Eday lives up to its name. - geograph.org.uk - 530459.jpg | caption = Red Head at the north end of Eday. The lower and steeper part of the cliff is formed of Middle Eday Sandstone, whereas the upper less steep part is formed of Eday Marl | type = Group | age = Givetian (Devonian) | period = Givetian | prilithology = sandstone | otherlithology = mudstone, siltstone, lava | namedfor = Eday | namedby = | region = Orkney | country = Scotland | coordinates = | unitof = Old Red Sandstone Supergroup | subunits = Upper Eday Sandstone Formation, Eday Marl Formation, Middle Eday Sandstone Formation, Eday Flagstone Formation, Lower Eday Sandstone Formation, Hoy Sandstone Formation | underlies = not overlain | overlies = Caithness Flagstone Group | thickness = over 2000 m | extent = Orkney Islands | area = | map = | map_caption = }} The Eday Group is a Devonian lithostratigraphic group (a sequence of rock strata) in Orkney, northern Scotland.[1] The name is derived from the island of Eday where the strata are exposed in coastal cliffs.[2] OutcropsThese rocks are exposed throughout Orkney, notably in coastal cliffs of Eday and western Sanday, South Ronaldsay and the Deerness peninsula of Mainland. There are spectacular exposures of the Hoy Sandstone Formation and particularly the Trowie Glen Sandstone Member in the precipitous cliffs of Hoy's west coast. Lithology and stratigraphyThe Group comprises the Upper Eday Sandstone Formation, Eday Marl Formation, Middle Eday Sandstone Formation, Eday Flagstone Formation, Lower Eday Sandstone Formation and the Hoy Sandstone Formation laid down in the shallow Orcadian Basin during the Givetian stage of the Devonian period. The sediments vary from fluvial to lacustrine to lagoonal. On the island of Hoy, the Hoy Sandstone is a particularly thick formation at whose base is the Hoy Volcanic member.[3] See also{{Portal|Earth sciences|Scotland|Paleontology|Devonian|Paleozoic}}
References1. ^{{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= Various Contributors to the Paleobiology Database|url= http://www.fossilworks.org/|accessdate= 8 July 2014|deadurl= yes|archiveurl= https://web.archive.org/web/20140731140924/http://fossilworks.org/|archivedate= 31 July 2014|df= }} 2. ^http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=EDY (BGS on-line lexicon of rock units) 3. ^British Geological Survey 1:100,000 scale geological map (Scotland) Orkney Islands (special sheet) 6 : Geological groups|Geologic formations of Scotland|Devonian System of Europe|Devonian Scotland|Givetian|Devonian Scotland |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。