30-613: Poole Basin is a geological formation that forms the western part of the much larger Hampshire Basin from which it is separated by the River Avon . The rim and bed of the basin are formed by chalk , within which lie the Tertiary sands and clays underlying the Dorset Heaths . The most extensive deposits here are those of the Poole Formation or Bagshot Beds . At one time the whole area
60-406: A result of the number of birds the harbour as become a popular spot for bird watchers . Seals occasionally appear in the harbour in winter. American hard-shelled clams have been found in the harbour spreading from an initial release site on the lower River Test . The harbour is also home to a population of Sand smelt . On 31 July 2008 a 26-foot (8-metre), 7-tonne northern bottlenose whale
90-758: A single larger area of deposition covering the whole of southeast England during the Palaeocene. The two basins were progressively separated by the emergence of the Weald-Artois Anticline during the Eocene. By the Oligocene the London Basin was wholly dry land, and only a small part of the Hampshire Basin, centred on the modern Solent, was an area of marine deposition. Langstone Harbour Langstone Harbour
120-573: A small island at the centre has, as planned, become a breeding ground for birds, particularly little terns . During the Second World War the harbour was used as Starfish decoy site to misdirect German bombers. The 2,085.4-hectare (5,153-acre) harbour was designated a biological Site of Special Scientific Interest in 1985. A ferry has operated between Portsmouth and Hayling Island across Langstone Harbour for more than 200 years; in 2022-23 it carried more than 47,000 passengers. The harbour
150-574: A trap for the Wytch Farm oil field . These blocks have moved vertically relative to each other during late Palaeozoic and Mesozoic times, resulting in considerable variations in the thickness of the various formations deposited over them before the chalk. Rocks of Lower Greensand ( Aptian ) age were deposited over an eroded surface, which ranges from Great Oolite (Early Jurassic Bathonian ) to Weald Clay (mid-Cretaceous Hauterivian ) in age. The chalk itself varies considerably in thickness, with
180-627: Is Creech Barrow Hill (193 m), the highest Tertiary hill in England, capped with Eocene limestone . 50°42′N 1°54′W / 50.7°N 1.9°W / 50.7; -1.9 Hampshire Basin The Hampshire Basin is a geological basin of Palaeogene age in southern England , underlying parts of Hampshire , the Isle of Wight , Dorset , and Sussex . Like the London Basin to
210-713: Is a 2,085.4-hectare (5,153-acre) biological Site of Special Scientific Interest in Hampshire . It is an inlet of the English Channel in Hampshire, sandwiched between Portsea Island to the south and west, Hayling Island to the south and east, and Langstone to the north. It is part of the Ramsar site of Langstone and Chichester Harbour Special Protection Area and Nature Conservation Review site. Parts are Special Areas of Conservation , or Local Nature Reserves , and some areas by
240-537: Is home to an extensive range of marine and bird life. Fifty species of fish have been found in the harbour. The harbour's bird life is even richer, the harbour hosting a wide range of species some of which are represented by over 10,000 individuals. This is in a large part due to the Royal Society for the Protection of Birds acquiring islands and a number of tidal areas in 1978 and turning them into bird sanctuaries. As
270-873: Is the chalk of the South Downs , Salisbury Plain and Cranborne Chase . The basin at its widest is around 30 miles (48 km), north-west to south-east, between Salisbury and Newport, Isle of Wight . The area west of the River Avon is usually known as the Poole Basin . The basin includes areas of forest and heath including Wareham Forest , Arne and the New Forest and the large south coast settlements of Bournemouth , Southampton and Portsmouth . The coast has many drowned valleys ( rias ) including The Solent , Poole Harbour , Southampton Water , Portsmouth Harbour , Chichester Harbour , Langstone Harbour , Pagham Harbour , Yarmouth , Cowes and Bembridge . In addition to
300-743: The Dorchester area in the west to Beachy Head in the east. Its southern boundary is marked by a monocline , the Purbeck Monocline , resulting in a near-vertical chalk ridge which forms the Purbeck Hills of Dorset, running under the sea from Old Harry Rocks to The Needles and the central spine of the Isle of Wight and continuing under the English Channel as the Wight- Bray monocline. The northern limit
330-487: The Hampshire and Isle of Wight Wildlife Trust , Farlington Marshes and Southmoor Nature Reserve West of Portsmouth is Portsmouth Harbour and the three linked harbours are important recreational and conservation areas as well as supporting commercial fishing and shipping. It is administered by the Langstone Harbour Board. The eastern boundary with Chichester Harbour is defined by a historic causeway known as
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#1732852858847360-407: The Hampshire and Isle of Wight Wildlife Trust . Historically, the harbour has been used for salt and sand production, as well as fishing and latterly leisure boating. A ferry across the mouth of the harbour has been in operation for more than 200 years. Langstone Harbour is an inlet of the English Channel in Hampshire, sandwiched between Portsea Island to the south and west, Hayling Island to
390-430: The 1990s a seven-year archaeology project took place before their history was lost to the seas. There are two smaller islands: Round Nap Island which is connected to South Binness Island by a tidal causeway and Oyster Island. Langstone Harbour was originally a river valley of one of the tributaries flowing into the then River Solent . With the end of the last ice age sea levels rose until sometime between 4000 and 3500BC
420-590: The Wade Way, which was originally the only crossing between Hayling Island and the mainland. It is now impassable, having been cut in two by a deep channel for the Portsmouth and Arundel Canal in the 1820s (for further information see Langstone ). Langstone Harbour contains a number of islands; Baker's Island ( SU694035 ), North Binness Island ( SU692046 ), South Binness Island ( SU698031 ) and Long Island ( SU701041 ). These are subject to erosion and during
450-766: The basin is a narrow coastal plain draining into the many harbours via small streams , and is crossed by larger rivers draining the Weald including the Arun and Adur . The main basin consists of an asymmetric syncline in the Cretaceous chalk, with a gentle dip southwards from Salisbury Plain terminating abruptly at a near vertical monocline in the south. The chalk surface dips from around 170 metres (560 ft) above sea level west of Winchester to 600 metres (2,000 ft) below sea level at Newport , before rising abruptly to around 200 metres (660 ft) above sea level in parts of
480-549: The central hills of the Isle of Wight and the Purbeck Hills. The chalk can be visualised as a thin layer draped over rigid blocks of older rocks at depth, which have moved vertically due to the Alpine Orogeny . Beneath the chalk the geology is complex. It is believed that a series of major blocks separated by faults trending NW-SE is fragmented into smaller blocks by numerous east-west trending faults ; one such block acts as
510-655: The end of the last ice age this system was disrupted by rising sea levels , which separated the Isle of Wight from the mainland . Today the western part of the basin drains via the rivers Frome and Piddle into Poole Harbour, and via the Stour and Avon directly to the English Channel. The central part drains into the Solent (directly or via Southampton Water), through the Lymington River , Test , Itchen , Meon , Hamble , Western Yar , Medina and Eastern Yar . The eastern part of
540-513: The harbour took on the form it would have until the 18th century. For much of its history the harbour has been an area of salt production. The Domesday Book records three salthouses around the harbour and by the early 17th century a saltern at Copnor was well established. Here a large shallow area of the harbour meant that even without further improvement salt could be extracted from the area after each tide. The Copnor saltern ceased production in 1800 but salt production continued elsewhere in
570-413: The harbour until 1933. In 1771 Farlington Marshes were reclaimed from the north of the harbour. Oyster farming began in the harbour around 1820 with winkle and clam cultivation probably starting around much the same time. Production ceased in the 1950s. An attempt at oyster farming in the 1980s soon failed. In 1997 work began to turn the remains into an artificial lagoon. The lagoon which has
600-509: The harbour was called into question when samples taken in 2022 were found to contain traces of numerous chemical compounds including prescribed medicines. The harbour has outflow from a water treatment plant. In most years since 2011, the harbour made a loss. About a third of its income comes from dredged sand, which is reliant upon a single dredger. In 2023 a government grant of £233,000 would be spent on upgrading facilities for local fishing and leisure boating. There are several boat wrecks in
630-577: The harbour. One of these is a tug dating from 8 May 1941. The tug named the Irishman was sunk by a magnetic mine and now rests partially submerged at low tide. A slightly older wreck dating from 1926 is a Bucket dredger named the Withern . Of unrecorded age is the wreck of the Excelsior , an 80-foot-long barge. The harbour also contains a wrecked landing craft that rests with its bows almost permanently above
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#1732852858847660-495: The northeast, it is filled with sands and clays of Paleocene and younger ages and it is surrounded by a broken rim of chalk hills of Cretaceous age. The Hampshire Basin is the traditional name for the landward section of a basin underlying the northern English Channel and much of central southern England, known more fully as the Hampshire- Dieppe Basin. It stretches a little over 100 miles (160 km) from
690-483: The northern Isle of Wight; the Headon Hill beds of the New Forest , formerly classified as Oligocene, are now regarded as late Eocene . The simple basin structure is complicated by localised folding. A smaller outcrop of Palaeocene and Eocene deposits occurs in a small syncline to the south-east of Salisbury . An anticline to the north of Portsmouth results in the significant chalk ridge of Portsdown Hill within
720-455: The northern half of the Isle of Wight which lies within the basin, the harbours contain inhabited islands including Brownsea Island , Portsea Island , Hayling Island and Thorney Island . The Hampshire Basin has no single dominant river . In former times the Frome and Solent rivers would have drained much of the basin from west to east, fed by tributaries flowing from the north and south. At
750-549: The perimeter of the basin, from the coast at Studland , around the perimeter of the Dorset heathlands, north and east past Romsey , swinging southeast past Eastleigh and eastwards towards Chichester , Worthing and Shoreham-by-Sea . Within this rim, over the greater part of the basin is an outcrop of younger Eocene deposits, the Bagshot , Bracklesham and Barton beds. The youngest, Oligocene beds ( Bouldnor Formation ) only occur on
780-586: The results of a marine transgression progressing across into Dorset from the east. There is evidence that the top of the Upper Greensand to the west is the same age as the oldest chalk in the Isle of Wight. Above the chalk the basin contains Palaeogene sediments ranging from Thanetian ( Palaeocene ) age to Rupelian ( Oligocene ) age. The oldest beds, the Lambeth Group (' Reading Beds') and Thames Group (' London Clay ') outcrop in narrow bands towards
810-516: The south and east, and Langstone to the north. It is part of the Ramsar site of Langstone and Chichester Harbour , Special Protection Area and Nature Conservation Review site, Grade I. Parts of it are in Solent Maritime and Solent and Isle of Wight Lagoons Special Areas of Conservation . Three areas are Local Nature Reserves , Farlington Marshes West Hayling and The Kench, Hayling Island . Two areas are nature reserves managed by
840-641: The younger sediments; the London Clay to the north contains the Forest of Bere . A similar structure further east causes chalk to outcrop between Bognor Regis and Worthing , separated from the chalk of the South Downs by a belt of Reading Beds and London Clay continuing from Havant through Chichester and south of Arundel to the coast at Lancing . It is likely that the London and Hampshire basins were initially part of
870-640: Was almost all heathland lying on acidic soils. Between the chalk perimeter and the central heaths is a belt where the Reading Beds and London Clays surface, giving rise to richer, albeit still acidic, soils. Deposits of plateau and valley gravels overlie the sands of the Poole Formation, but their soils are likewise poor and acidic. Erosive forces have resulted in an undulating landscape with considerable local variation from narrow, steep-sided valleys and escarpments to areas of flat terrain. The highest point
900-647: Was beached on a mudflat in Langstone Harbour. A rescue operation was carried out to try to save the whale off the south coast of England and managed to free the whale from mudflats using a special lifting pontoon but it remained in shallow water. A decision was made to give the whale a lethal injection as a blood test revealed that it was suffering from kidney failure. If the whale swam into deeper water it could take up to two days to die naturally from renal failure. The whale ended up about 3,000 miles (4,800 km) off course due to its illness. The quality of water in
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