Related Research Articles
The Chalk Group is the lithostratigraphic unit which contains the Upper Cretaceous limestone succession in southern and eastern England. The same or similar rock sequences occur across the wider northwest European chalk 'province'. It is characterised by thick deposits of chalk, a soft porous white limestone, deposited in a marine environment.
Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite. Greensand is also loosely applied to any glauconitic sediment.
The Lambeth Group is a stratigraphic group, a set of geological rock strata in the London and Hampshire Basins of southern England. It comprises a complex of vertically and laterally varying gravels, sands, silts and clays deposited between 56-55 million years before present during the Ypresian age. It is found throughout the London Basin with a thickness between 10m and 30m, and the Hampshire Basin with a thickness between 50m and less than 25m. Although this sequence only crops out in these basins, the fact that it underlies 25% of London at a depth of less than 30m means the formation is of engineering interest for tunnelling and foundations.
The Hannut Formation is a geologic formation in the subsurface of northern Belgium. The formation consists of marine clay and silt, alternating with more sandy layers. On top of this the lithology changes to limestone, siltstone and sandstone and the top of the formation is formed by a layer of glauconite bearing sand. The Hannut Formation was formed during the early to middle Thanetian age.
The Gentbrugge Formation is a geologic formation in the west of Belgium. The formation crops out in East Flanders and West Flanders and also occurs in the subsurface of the Province of Antwerp. It consists of marine clay, silt and sand, deposited in the shallow sea that covered northern Belgium during the Ypresian age.
The Lower Greensand Group is a geological unit present across large areas of Southern England. It was deposited during the Aptian and Albian stages of the Early Cretaceous. It predominantly consists of sandstone and unconsolidated sand that were deposited in shallow marine conditions.
Haffield Breccia, or Clent Breccia, consist of a texturally immature compacted gravel, rich in volcanic clasts with some sedimentary rocks, in a sandy or muddy matrix, which outcrops in the English Midlands, in South Staffordshire, Birmingham and the Malverns. It is thought to have been deposited by during flash floods in rivers that were flowing through a desert, somewhere between 200 and 280 million years ago during the Permian period. The gravel consists of angular fragments, showing that they have not been transported over long distances.
The geology of Suffolk in eastern England largely consists of a rolling chalk plain overlain in the east by Neogene clays, sands and gravels and isolated areas of Palaeocene sands. A variety of superficial deposits originating in the last couple of million years overlie this 'solid geology'.
The geology of Essex in southeast England largely consists of Cenozoic marine sediments from the Palaeogene and Neogene periods overlain by a suite of superficial deposits of Quaternary age.
The Ferruginous Sands is a geologic formation in England. It preserves fossils dating back to the Aptian Stage of the Cretaceous period. It consists of "a number of heavily bioturbated coarsening-upward units each comprising dark grey sandy muds or muddy sands passing up into fine-to medium-grained grey to green glauconitic sands." The dinosaur Vectaerovenator inopinatus is known from the formation. Shark teeth are also known from the formation, including those of an indeterminate lamniform shark and Palaeospinax.
The Thanet Formation is a geological formation found in the London Basin of southeastern England. It is of early to mid-Thanetian age and gave its name to that stratigraphic interval. It was previously known as the Thanet Beds, the Thanet Sands and the Thanet Sand Formation. It was named after the Isle of Thanet. The type sections are Herne Bay in Kent for the upper part of the formation and Pegwell Bay for the lower part. It lies unconformably on the Late Cretaceous Chalk Group. It unconformably underlies the Lambeth Group, generally the Upnor Formation but in Essex it is the Reading Formation.
The Corallian Group or Corallian Limestone is a geologic group in England. It is predominantly a coralliferous sedimentary rock, laid down in the Oxfordian stage of the Jurassic. It is a hard variety of "coral rag". Building stones from this geological structure tend to be irregular in shape. It is often found close to seams of Portland Limestone. It is a younger limestone than its near-neighbour, the Oolitic, as found in the Cotswolds, in Gloucestershire. It is laterally equivalent to and interfingers with units of the Ancholme Group.
The geology of West Sussex in southeast England comprises a succession of sedimentary rocks of Cretaceous age overlain in the south by sediments of Palaeogene age. The sequence of strata from both periods consists of a variety of sandstones, mudstones, siltstones and limestones. These sediments were deposited within the Hampshire and Weald basins. Erosion subsequent to large scale but gentle folding associated with the Alpine Orogeny has resulted in the present outcrop pattern across the county, dominated by the north facing chalk scarp of the South Downs. The bedrock is overlain by a suite of Quaternary deposits of varied origin. Parts of both the bedrock and these superficial deposits have been worked for a variety of minerals for use in construction, industry and agriculture.
The Bridport Sand Formation is a formation of Toarcian age found in the Worcester and Wessex Basins of central and southern England. It forms one of the reservoir units in the Wytch Farm oilfield in Dorset. The sandstone is very-fine grained to fine-grained and contains regular narrow bands that are calcite-cemented and more resistant to weathering, giving it a characteristic banded appearance at outcrop, such as in the cliffs between Bridport and Burton Bradstock in Dorset. It is named for Bridport and has previously been known as the Midford Sand(s), Cotteswold Sands, Yeovil Sands and Upper Lias Sand(s). It forms a locally important aquifer, particularly around Yeovil.
This article describes the geology of the Broads, an area of East Anglia in eastern England characterised by rivers, marshes and shallow lakes ('broads'). The Broads is designated as a protected landscape with 'status equivalent to a national park'.
This article describes the geology of the New Forest, a national park in Hampshire, in Southern England.
Finedon Top Lodge Quarry, also known as Finedon Gullet is a 0.9-hectare (2.2-acre) geological Site of Special Scientific Interest east of Wellingborough in Northamptonshire. It is a Geological Conservation Review site revealing a sequence of middle Jurassic limestones, sandstones and ironstones, and is the type section for a sequence of sedimentary rocks known as the 'Wellingborough Member'. It was created by quarrying for the underlying ironstone for use at Wellingborough and Corby Steelworks; the ore was transported by the 1,000 mm gauge Wellingborough Tramway.
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 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 the South Downs National Park in South East England comprises a gently folded succession of sedimentary rocks from the Cretaceous and early Palaeogene periods overlain in places by a range of superficial deposits from the last 2.6 million years. Whereas the South Downs are formed from the Late Cretaceous age chalk, the South Downs National Park extends into the Weald to the north of the range and thereby includes older rock strata dating from the Early Cretaceous including sandstones and mudstones. The youngest solid rocks are found on the southern fringes of the National Park in the eastern extension of the Hampshire Basin and include sand, silt and clay deposited during the Palaeocene and Eocene epochs.
References
- ↑ "Harwich Formation". The BGS Lexicon of Named Rock Units. British Geological Survey . Retrieved 31 July 2016.
- 1 2 Skipper, J.; Edgar, J. (2020). "The Harwich Formation in London – The legacy of Chris King". Proceedings of the Geologists' Association. 131 (5): 474–485. doi:10.1016/j.pgeola.2019.09.001.
- ↑ British Geological Survey. "Swanscombe Member" . Retrieved 18 April 2024.
- 1 2 British Geological Survey. "Oldhaven Member" . Retrieved 18 April 2024.
- ↑ Edgar, J.; Ghail, R.C.; Lawrence, J.; Skipper, J.; Mason, P.J. (2022). "The impact of facies variability within the Harwich Formation on ground engineering in the London area, UK". Quarterly Journal of Engineering Geology and Hydrogeology. 55 (1). doi:10.1144/qjegh2020-136.
- ↑ British Geological Survey. "Wrabness Member" . Retrieved 18 April 2024.
- ↑ British Geological Survey. "Blackheath Member" . Retrieved 18 April 2024.
- ↑ British Geological Survey. "Orwell Member" . Retrieved 18 April 2024.
- ↑ "GLA 65 Old Gravel Pit, Blackheath (Vanbrugh Pit), LIGS" (PDF). Guide to London’s Geological Sites. Retrieved 18 April 2024.
- ↑ "GLA 24: Old Gravel Pit, Blackheath, Potential LIGS" (PDF). Guide to London’s Geological Sites. Retrieved 18 April 2024.