Great Scar Limestone Group | |
---|---|
Stratigraphic range: Arundian-Brigantian | |
Type | Group |
Unit of | Carboniferous Limestone Supergroup |
Sub-units | See text |
Underlies | Yoredale Group |
Overlies | Ravenstonedale Group |
Thickness | Up to 800 m (2,600 ft) |
Lithology | |
Primary | Limestone |
Other | Mudstone, siltstone, sandstone |
Location | |
Region | England |
Country | United Kingdom |
Extent | Pennines to Isle of Man |
The Great Scar Limestone Group is a lithostratigraphical term referring to a succession of generally fossiliferous rock strata which occur in the Pennines in northern England and in the Isle of Man within the Tournaisian and Visean stages of the Carboniferous Period.
It is contained within the Carboniferous Limestone Supergroup. [1]
The sequence in the Stainmore Trough is thus (youngest at top):
On the Alston Block corresponding to the North Pennines, the sequence contains the Melmerby Scar Limestone Formation.
In the Orton area, the sequence is:
In south Cumbria, the sequence is: [2]
On the Isle of Man, the following sequence is identified in the Castletown area: [3] [4]
The North Pennines is the northernmost section of the Pennine range of hills which runs north–south through northern England. It lies between Carlisle to the west and Darlington to the east, straddling the borders of the counties of Cumbria, Durham, Northumberland and North Yorkshire. It is bounded to the north by the Tyne Valley and to the south by the Stainmore Gap.
The geology of the county of Shropshire, England is very diverse with a large number of periods being represented at outcrop. The bedrock consists principally of sedimentary rocks of Palaeozoic and Mesozoic age, surrounding restricted areas of Precambrian metasedimentary and metavolcanic rocks. The county hosts in its Quaternary deposits and landforms, a significant record of recent glaciation. The exploitation of the Coal Measures and other Carboniferous age strata in the Ironbridge area made it one of the birthplaces of the Industrial Revolution. There is also a large amount of mineral wealth in the county, including lead and baryte. Quarrying is still active, with limestone for cement manufacture and concrete aggregate, sandstone, greywacke and dolerite for road aggregate, and sand and gravel for aggregate and drainage filters. Groundwater is an equally important economic resource.
Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and 325 million years ago. Within England and Wales, the entire limestone succession, which includes subordinate mudstones and some thin sandstones, is known as the Carboniferous Limestone Supergroup.
Millstone Grit is any of a number of coarse-grained sandstones of Carboniferous age which occur in the British Isles. The name derives from its use in earlier times as a source of millstones for use principally in watermills. Geologists refer to the whole suite of rocks that encompass the individual limestone beds and the intervening mudstones as the Millstone Grit Group. The term Millstone Grit Series was formerly used to refer to the rocks now included within the Millstone Grit Group together with the underlying Edale Shale Group.
The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale are Permo-Triassic. The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the south east are Cretaceous chalk uplands. The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages. The strata become gradually younger from west to east.
The geology of Monmouthshire in southeast Wales largely consists of a thick series of sedimentary rocks of different types originating in the Silurian, Devonian, Carboniferous, Triassic and Jurassic periods.
The Portland Group is a Late Jurassic (Tithonian) lithostratigraphic group in South East England. The name is derived from the Isle of Portland in Dorset where the strata are exposed and have been extensively worked. Rocks of this age have in the past been called the Portlandian stage by geologists, which corresponds with the late Tithonian stage of the internationally used geological timescale.
The geology of Lancashire in northwest England consists in the main of Carboniferous age rocks but with Triassic sandstones and mudstones at or near the surface of the lowlands bordering the Irish Sea though these are largely obscured by Quaternary deposits.
The geology of County Durham in northeast England consists of a basement of Lower Palaeozoic rocks overlain by a varying thickness of Carboniferous and Permo-Triassic sedimentary rocks which dip generally eastwards towards the North Sea. These have been intruded by a pluton, sills and dykes at various times from the Devonian Period to the Palaeogene. The whole is overlain by a suite of unconsolidated deposits of Quaternary age arising from glaciation and from other processes operating during the post-glacial period to the present. The geological interest of the west of the county was recognised by the designation in 2003 of the North Pennines Area of Outstanding Natural Beauty as a European Geopark.
The geology of Tyne and Wear in northeast England largely consists of a suite of sedimentary rocks dating from the Carboniferous and Permian periods into which were intruded igneous dykes during the later Palaeogene Period.
The Bluefield Formation is a geologic formation in West Virginia. It preserves fossils dating back to the Mississippian subperiod of the Carboniferous period. Sediments of this age formed along a large marine basin lying in the region of what is now the Appalachian Plateau. The Bluefield Formation is the lowest section of the primarily siliciclastic Mauch Chunk Group, underlying the Stony Gap Sandstone Member of the Hinton Formation and overlying the limestone-rich Greenbrier Group.
The Pembroke Limestone Group is a stratigraphic unit of Courceyan to Brigantian age found in southern Wales and northern Somerset. It forms part of the Carboniferous Limestone Supergroup. These carbonate rocks developed in platform and ramp environments and are up to 1025m thick in places.
The geology of Northumberland in northeast England includes a mix of sedimentary, intrusive and extrusive igneous rocks from the Palaeozoic and Cenozoic eras. Devonian age volcanic rocks and a granite pluton form the Cheviot massif. The geology of the rest of the county is characterised largely by a thick sequence of sedimentary rocks of Carboniferous age. These are intruded by both Permian and Palaeogene dykes and sills and the whole is overlain by unconsolidated sediments from the last ice age and the post-glacial period. The Whin Sill makes a significant impact on Northumberland's character and the former working of the Northumberland Coalfield significantly influenced the development of the county's economy. The county's geology contributes to a series of significant landscape features around which the Northumberland National Park was designated.
The Holkerian is a sub-stage of the Viséan stage of the International Commission on Stratigraphy (ICS) geological timescale. It is one of five sub-stages commonly used in the Viséan stage within stratigraphy by British, Irish and other geologists outside the US and Asia.
The geology of the Isle of Man consists primarily of a thick pile of sedimentary rocks dating from the Ordovician period, together with smaller areas of later sedimentary and extrusive igneous strata. The older strata was folded and faulted during the Caledonian and Acadian orogenies The bedrock is overlain by a range of glacial and post-glacial deposits. Igneous intrusions in the form of dykes and plutons are common, some associated with mineralisation which spawned a minor metal mining industry.
This article describes the geology of Dartmoor National Park in Devon, in south-west England. Dartmoor gained national park status in 1951 but the designated area of 954 km2 (368 sq mi) extends beyond the upland of Dartmoor itself to include much of the surrounding land, particularly in the northeast. The geology of the national park consists of a 625 km2 (241 sq mi) core of granite intruded during the early Permian period into a sequence of sedimentary rocks originating in the Devonian and Carboniferous periods. These rocks were faulted and folded, sometimes, intensely, during the Variscan orogeny. Thermal metamorphism has also taken place around the margins of the granite pluton altering the character of the sedimentary rocks whilst mineral veins were emplaced within the granite. A small outlier of Palaeogene sediments occurs on the eastern boundary of the national park.
The geology of Northumberland National Park in northeast England includes a mix of sedimentary, intrusive and extrusive igneous rocks from the Palaeozoic and Cenozoic eras. Devonian age volcanic rocks and a granite pluton form the Cheviot massif. The geology of the rest of the national park is characterised largely by a thick sequence of sedimentary rocks of Carboniferous age. These are intruded by Permian dykes and sills, of which the Whin Sill makes a significant impact in the south of the park. Further dykes were intruded during the Palaeogene period. The whole is overlain by unconsolidated sediments from the last ice age and the post-glacial period.
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 Peak District National Park in England is dominated by a thick succession of faulted and folded sedimentary rocks of Carboniferous age. The Peak District is often divided into a southerly White Peak where Carboniferous Limestone outcrops and a northerly Dark Peak where the overlying succession of sandstones and mudstones dominate the landscape. The scarp and dip slope landscape which characterises the Dark Peak also extends along the eastern and western margins of the park. Although older rocks are present at depth, the oldest rocks which are to be found at the surface in the national park are dolomitic limestones of the Woo Dale Limestone Formation seen where Woo Dale enters Wye Dale east of Buxton.
The geology of Staffordshire in the West Midlands region of England is largely characterised by sedimentary bedrock of late Palaeozoic to early Mesozoic age overlain by a suite of superficial materials deposited during the Quaternary period. The extraction of coal, limestone and clay have been significant industries within the county.