| 词条 | Hunts Bay Oolite |
| 释义 |
| name = Hunts Bay Oolite | image = | caption = | type = Formation | age = Holkerian | prilithology = Carbonate rock | otherlithology = Oolite | namedfor = Hunts Bay, Gower Peninsula | namedby = | region = Wales | country = United Kingdom | coordinates = | unitof = Carboniferous Limestone Supergroup | subunits = Pembroke Limestone Group | underlies = Oxwich Head Limestone Formation | overlies = High Tor Limestone Formation | thickness = | extent = | area = | map = | map_caption = }} Hunts Bay Oolite is an oolitic carboniferous limestone geological formation found in the south Wales region. It is named after Hunts Bay on the Gower peninsula, south-south west of Bishopston, where a significant amount of the limestone forms the cliffs there. Hunts Bay Oolite is a sub-group of the Pembroke Limestone Group which itself is part of the Carboniferous Limestone Supergroup.[1][2][3] Oolite means 'egg stone': very small grains (up to 2mm) form by accumulating precipitated minerals, usually calcium carbonate. These ooids, created in a warm, tropical environment, are the precursors to the limestone.[4][5] The Hunts Bay Oolite extends from Pembroke in the West to Monmouth and Chepstow in the East and northwards into the Dowlais formation around Merthyr Tydfil. Fossils, such as brachiopods and crinoids associated with a shallow sea environment, can be found in the rock. East of the south Wales coalfield and in the south east the rock is increasingly dolomitised (where some calcium is replaced by magnesium).[1] This subgroup lies in time largely in the (British geological) Holkerian substage of the Viséan stage of the stratigraphic column, from 337 to 333.5 million years ago. At the time, the rocks of Europe were much closer to the equator.[6][7] See also{{Portal|Earth sciences|Wales|Paleontology|Carboniferous|Paleozoic}}
References1. ^1 {{cite web|url=http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=HBO/|last=British Geological Survey|title=Hunts Bay Oolite Subgroup|accessdate=21 October 2017|website=www.bgs.ac.uk}} 2. ^{{cite web|url=http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=PEMB/|last=British Geological Survey|title=Pembroke Limestone Group|accessdate=21 October 2017|website=www.bgs.ac.uk}} 3. ^{{cite web|url=http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=CL/|last=British Geological Survey|title=Carboniferous Limestone Supergroup|accessdate=18 October 2017|website=www.bgs.ac.uk}} 4. ^{{cite web|url=http://orca.cf.ac.uk/54988/|last=Online Research @ Cardiff|title=Sedimentology, sea-level history and porosity evolution of the Holkerian (Lower Carboniferous) of Gower|accessdate=21 October 2017|website=orca.cf.ac.uk}} 5. ^{{cite journal|url=http://nora.nerc.ac.uk/16659/1/Ch5_S_Wales_text_v5_edited.pdf/|last1=Waters (Ed.)|first1=Colin|title=A revised correlation of Carboniferous rocks in the British Isles: South Wales|journal=Geological Society of London|pages=29–36|date=2011|accessdate=21 October 2017}} 6. ^{{cite web|url=http://earthwise.bgs.ac.uk/index.php/Visean,_Dinantian,_Carboniferous,_Wales/|last=Visean, Dinantian, Carboniferous, Wales|title=Visean, Dinantian, Carboniferous, Wales|accessdate=21 October 2017|website=earthwise.bgs.ac.uk}} 7. ^{{cite web|url=https://www.bgs.ac.uk/downloads/start.cfm?id=312/|last=BGS Geological timechart|title=BGS Geological timechart|accessdate=21 October 2017|website=www.bgs.ac.uk}}
2 : Carboniferous System of Europe|Carboniferous Wales |
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