Related Research Articles
The Howgill Fells are uplands in Northern England between the Lake District and the Yorkshire Dales, lying roughly within a triangle formed by the towns of Sedbergh and Kirkby Stephen and the village of Tebay. The name Howgill derives from the Old Norse word haugr meaning a hill or barrow, plus gil meaning a narrow valley.
The Windermere Supergroup is a geological unit formed during the Ordovician to Silurian periods ~450 million years ago, and exposed in northwest England, including the Pennines and correlates along its strike, in the Isle of Man and Ireland, and down-dip in the Southern Uplands and Welsh Borderlands. It underlies much of north England's younger cover, extending south to East Anglia. It formed as a foreland basin, in a similar setting to the modern Ganges basin, fronting the continent of Avalonia as the remains of the attached Iapetus ocean subducted under Laurentia.
The Cornbrash Formation is a Middle Jurassic geological formation in England. It ranges in age from Bathonian to Callovian, the uppermost part of the Middle Jurassic. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. The name Cornbrash is an old English agricultural name applied in Wiltshire to a variety of loose rubble or brash which, in that part of the country, forms a good soil for growing corn. The name was adopted by William Smith for a thin band of shelly limestone which, in the south of England, breaks up in the manner indicated. Although only a thin group of rocks, it is remarkably persistent; it may be traced from Weymouth to the Yorkshire coast, but in north Lincolnshire it is very thin, and probably dies out in the neighborhood of the Humber. It appears again, however, as a thin bed in Gristhorpe Bay, Cayton Bay, Wheatcroft, Newton Dale and Langdale. In the inland exposures in Yorkshire it is difficult to follow on account of its thinness, and the fact that it passes up into dark shales in many places the so-called clays of the Cornbrash, with Avicula echinata. The Cornbrash is of little value for building or road-making, although it is used locally; in the south of England it is not oolitic, but in Yorkshire it is a rubbly, marly, frequently ironshot oolitic limestone. In Bedfordshire it has been termed the Bedford limestone.
The Magnesian Limestone is a suite of carbonate rocks in north-east England dating from the Permian period. The outcrop stretches from Nottingham northwards through Yorkshire and into County Durham where it is exposed along the coast between Hartlepool and South Shields. The term has now been discontinued in formal use though it appears widely in popular and scientific literature on the geology of northern England.
The Great Estuarine Group is a sequence of rocks which outcrop around the coast of the West Highlands of Scotland. Laid down in the Hebrides Basin during the middle Jurassic, they are the rough time equivalent of the Inferior and Great Oolite Groups found in southern England.
The Sherwood Sandstone Group is a Triassic lithostratigraphic group which is widespread in Britain, especially in the English Midlands. The name is derived from Sherwood Forest in Nottinghamshire which is underlain by rocks of this age. It has economic importance as the reservoir of the Morecambe Bay gas field, the second largest gas field in the UK.
The Caerfai Group is a Cambrian lithostratigraphic group in west Wales. The name is derived from Caerfai Bay on the north coast of St Brides Bay on the Pembrokeshire coast where the strata are well exposed in coastal cliffs. This rock succession has previously been known variously as the Caerfai Series, Caerfai Formation and Caerfai Beds and largely ascribed to the British regional stratigraphic unit Comley Epoch, though these terms are now obsolete.
The Dent Group is a group of Upper Ordovician sedimentary and volcanic rocks in north-west England. It is the lowermost part of the Windermere Supergroup, which was deposited in the foreland basin formed during the collision between Laurentia and Avalonia. It lies unconformably on the Borrowdale Volcanic Group. This unit was previously known as the Coniston Limestone Group or Coniston Limestone Formation and should not be confused with the significantly younger Coniston Group.
The Riccarton Group is a Silurian lithostratigraphic group in southern Scotland and northern England. The name is derived from Riccarton in the Edinburgh area. The rocks of the Riccarton Group have also previously been known as the Riccarton Formation and the Riccarton and Raeberry Castle Beds. The Group comprises around 500m thickness of greywackes, mudstones and siltstones which are faulted and folded.
The geology of England's Lake District is dominated by sedimentary and volcanic rocks of mainly Ordovician age underpinned by large granitic intrusions. Younger sedimentary sequences outcrop on the edges of the Lake District area, with Silurian to the south, Carboniferous to the north, east and west and Permo-Triassic to the west and east. The entire area was covered by a Mesozoic sequence that was eroded off during Paleogene uplift related to the opening of the North Atlantic. During the Quaternary the area was affected by repeated glaciations, which sculpted the current mountainous landscape.
High Cup Gill, almost a geometrically perfect U-shaped chasm, is a valley deeply incised into the Pennine scarp to the northeast of Appleby-in-Westmorland in Cumbria and within the North Pennines AONB in northern England. It is considered to be glacial in origin, ice having over-ridden the area during successive ice ages. To its southeast is Murton Fell whilst Dufton Fell is to the north.
The Ravenstonedale Group is a Carboniferous lithostratigraphic group in the Pennines of northern England. The name is derived from the locality of Ravenstonedale in southeast Cumbria. The rocks of the Ravenstonedale Group have also previously been referred to as the Ravenstonedale Limestone. The group comprises limestones and oolites and some sandstones and shales which reach a maximum thickness of 380m in the Brough area. It is divided into a lower Raydale Dolomite Formation which is overlain by the Marsett Formation and then by an upper Penny Farm Gill Formation.Its base is everywhere an unconformity with Ordovician and Devonian rocks beneath.
The Kendal Group is a Silurian lithostratigraphic group in the southern Lake District and the Howgill Fells of northern England. The name is derived from the town of Kendal in Cumbria. The Group is included within the Windermere Supergroup. The group comprises couplets of siltstone and mudstone along with some turbiditic sandstones and which may exceed a thickness of 4200m. Its lower unit is the Bannisdale Formation above which is the Kirkby Moor Formation. Some of the rocks of the latter were earlier included in the Underbarrow and Scout Hill Flag formations.
The Coniston Group is a Silurian lithostratigraphic group in the southern Lake District and north-west Pennines of northern England. The name is derived from the small town of Coniston in Cumbria. The rocks of the Group have also previously been referred to as the Coniston Grits or Coniston Grits Formation and Coniston Subgroup. The group comprises sandstones and siltstones and some laminated hemipelagites which achieve a thickness of between 1400 and 1900m. Overlain by the Bannisdale Formation of the Kendal Group and underlain by the Wray Castle Formation of the Tranearth Group, it is divided into several formations. These are, in ascending order : Wray Castle, Gawthwaite, Latrigg, Poolscar, Moorhow and Yewbank.
The Stockdale Group is a Silurian lithostratigraphic group in the southern Lake District and Howgill Fells of the Pennines of northern England. The name is derived from the locality of Stockdale near the top of Longsleddale in Cumbria. It is included within the Windermere Supergroup. The rocks of the Group have also previously been referred to as the Stockdale Shales or Stockdale Subgroup. The group comprises limestones and oolites and some sandstones and shales which reach a maximum thickness of 120m in the area. It is divided into a lower Skelgill Formation which is overlain by an upper Browgill Formation.
The Manx Group is an Ordovician lithostratigraphic group in the Isle of Man in the Irish Sea. The name is derived from the name of the island which is largely formed from them; these rocks have also previously been referred to as the Manx Slates or Manx Slates Series. The group comprises dark mudstones with siltstone laminae and some sandstones and which exceed a thickness of 3000m. It is divided into a lowermost Glen Dhoo Formation which is overlain by the Lonan, Mull Hill, Creg Agneash and Maughold formations in ascending order. A fault separates these from the overlying Barrule, Injebreck, Glen Rushen and Creggan Mooar formations which are in turn separated by a fault from an overlying Ladyport Formation.
The Dalby Group is a Silurian lithostratigraphic group on the west coast of the Isle of Man in the Irish Sea. The name is derived from the village of Dalby near the west coast of the island. Together with those of the adjoining Manx Group, the rocks of the Group have also previously been referred to as the Manx Slates or Manx Slate Series. The group comprises wacke sandstones with siltstones and mudstones which reach a thickness of about 1200m in the west of the island. It contains only the single Niarbyl Formation which is exposed along the coast between Niarbyl Point and the town of Peel to the north.
Howgills in Letchworth Garden City, Hertfordshire, England, is a Grade II listed building on the Register of Historic England in use as a Meeting House for the Society of Friends (Quakers).
The geology of the Yorkshire Dales National Park in northern England largely consists of a sequence of sedimentary rocks of Ordovician to Permian age. The core area of the Yorkshire Dales is formed from a layer-cake of limestones, sandstones and mudstones laid down during the Carboniferous period. It is noted for its karst landscape which includes extensive areas of limestone pavement and large numbers of caves including Britain's longest cave network.
The geology of the North York Moors National Park in northern England is provided largely by a thick southerly dipping sequence of sedimentary rocks deposited in the Cleveland Basin during the Jurassic Period. A series of ice ages during the Quaternary period has left a variety of glacial deposits, particularly around the margins of the National Park.
References
- ↑ "Tranearth Group". The BGS Lexicon of Named Rock Units. British Geological Survey. Retrieved January 20, 2019.
- The Geological Society (2006). Brenchley, P.J. (ed.). The Geology of England (2. ed.). London: Geological Society Publishing. pp. 124, 126. ISBN 9781862392007.