Downton Castle SandstoneThe Downton Castle Sandstone is a geologic formation in England. It preserves fossils dating back to the Silurianperiod. As its name would suggest the formation predominantly consists of sandstone with minor siltstone and mudstone. The oldest known Trigonotarbid is known from the formation. See alsoGrey DowntonianList of fossiliferous stratigraphic units in EnglandReferencesVarious Contributors to the Paleobiology Database.Ledbury FormationThe Ledbury Formation is a geologic formation in Herefordshire, England. The shale formation preserves fossils dating back to the Silurian period.
ShaleShale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g., kaolin, Al2Si2O5(OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. Shale is characterized by its tendency to split into thin layers (laminae) less than one centimeter in thickness. This property is called fissility. Shale is the most common sedimentary rock.
Ludlow EpochSubdivision of the Silurian according to the ICS, as of 2024.Vertical axis scale: Millions of years agoEtymologyName formalityFormalName ratified1980Usage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionFAD of the GraptoliteLower boundary GSSP, Ludlow, U.K.52°21′33″N2°46′38″W / 52.3592°N 2.7772°W / 52.3592; -2.7772Lower GSSP ratified1980Upper boundary definitionFAD of the Graptolite Monograptus parultimus.Upper boundary GSSP, Prague-Řeporyje, Czech Republic50°01′40″N14°19′30″E / 50.0277°N 14.3249°E / 50.0277; 14.3249Upper GSSP ratified1984In the geological timescale, the Ludlow Epoch or Mid-Late Silurian (from 426.7 ± 1.5 million years ago to 422.7 ± 1.6 million years ago) occurred during the Silurian Period, after the end of the Homerian Age.
British IslesArchipelago in north-western EuropeThe British Isles, also called "these islands" in diplomatic settings, are an archipelago in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and OuterHebrides, the Northern Isles (Orkney and Shetland), and over six thousand smaller islands.
ScotlandCountry within the United KingdomScotland (Scots: Scotland; Scottish Gaelic: Alba) is a country that is part of the United Kingdom, consisting of the northern part of the island of Great Britain and adjacent islands, principally in the archipelagos of the Hebrides and the Northern Isles. In 2022 the country's population was about 5.4 million. Its capital city is Edinburgh, whilst Glasgow is the largest and the most populous of the cities in the country.
Aymestry LimestoneThe Aymestry Limestone is a fossiliferous limestone of Gorstian age (Upper Silurian) deposited in a warm shallow sea near the eastern margin of the Iapetus Ocean. It occurs in England in the Ludlow Group, between the Upper and Lower Ludlow Shales. It derives its name from Aymestrey (sic), Herefordshire, where it may be seen on both sides of the River Lugg.
SilurianSubdivision of the Silurian according to the ICS, as of 2024.Vertical axis scale: Millions of years agoEtymologyName formalityFormalSynonym(s)GotlandianUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitPeriodStratigraphic unitSystemFirst proposed byRoderick Murchison, 1835Time span formalityFormalLower boundary definitionFAD of the GraptoliteLower boundary GSSPDob's Linn, Moffat, United Kingdom55°26′24″N3°16′12″W / 55.4400°N 3.2700°W / 55.4400; -3.2700Lower GSSP ratified1984Upper boundary definitionFAD of the Graptolite Monograptus uniformisUpper boundary GSSPKlonk, Czech Republic49°51′18″N13°47′31″E / 49.8550°N 13.7920°E / 49.8550; 13.7920Upper GSSP ratified1972Atmospheric and climatic dataSea level above present dayAround 180 m, with short-term negative excursionsThe Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at 443.1 Ma (million years ago) to the beginning of the Devonian Period, 419.62 Ma.
IrelandIsland in the North Atlantic OceanIreland is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially named Ireland – a sovereign state covering five-sixths of the island) and Northern Ireland (part of the United Kingdom – covering the remaining sixth). It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel.
EnglandCountry within the United KingdomNot to be confused with United Kingdom.England is a country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and more than 100 smaller adjacent islands.
WalesCountry within the United KingdomWales (Welsh: Cymru) is a country that is part of the United Kingdom. Located on the island of Great Britain, it is bordered by the Irish Sea to the north and west, England to the east, the Bristol Channel to the south, and the Celtic Sea to the south-west. As of 2021, it had a population of 3.1 million. It has a total area of 21,218 square kilometres (8,192 sq mi) and over 2,700 kilometres (1,680 mi) of coastline.
Geological formationA geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers.*As an Amazon Associate I earn from qualifying purchases.