| 词条 | Penarth Group |
| 释义 |
| name = Penarth Group | image = File:Landscape marble treeline.jpg | caption = Cut face of Cotham Marble, from the Cotham Formation, showing the stromatolitic structures resembling a landscape | type = Group | age = {{fossilrange|Rhaetian|Rhaetian|Rhaetian}} | period = Rhaetian | prilithology = mudstone | otherlithology = limestone, sandstone | namedfor = Penarth | namedby = | region = | country = Great Britain, Ireland | coordinates = | unitof = New Red Sandstone Supergroup | subunits = Westbury Formation, Lilstock Formation | underlies = Lias Group | overlies = Mercia Mudstone Group | thickness = from 0 to more than 12m | extent = widespread | area = | map = | map_caption = }} The Penarth Group is a Rhaetian age (Triassic) lithostratigraphic group (a sequence of rock strata) which is widespread in Britain. It is named from the seaside town of Penarth near Cardiff in south Wales where strata of this age are exposed in coastal cliffs southwards to Lavernock Point. This sequence of rocks was previously known as the Rhaetic.[1] StratigraphyIt includes the Lilstock Formation and the underlying Westbury Formation. The Langport and Cotham Members, grey limestones of marine origin with associated mudstones, are recognised within the Lilstock Formation, itself named from Lilstock in west Somerset.[1][2] The Westbury Formation is named from Westbury-on-Severn in Gloucestershire.[3] IrelandIn 1999, the discovery of an ichthyosaur from Langport Member mudstones exposed at Waterloo Bay, Larne provided the most complete example of this in Northern Ireland.[4] References1. ^British Geological Survey 1:50,000 scale geological map sheet (England and Wales series) 326 Sidmouth {{UK-geologic-formation-stub}}2. ^1 The BGS Lexicon of Named Rock Units — Result Details: Penarth Group 3. ^The BGS Lexicon of Named Rock Units — Result Details: Westbury Formation 4. ^Unearthing the Larne Sea Dragon (2007) National Museums Northern Ireland 6 : Geology of the United Kingdom|Triassic System of Europe|Geology of England|Geology of Wales|Geology of Northern Ireland|Geology of Ireland |
| 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。