This article is largely based on an article in the out-of-copyright Encyclopædia Britannica Eleventh Edition, which was produced in 1911. It should be brought up to date to reflect subsequent history or scholarship (including the references, if any). When you have completed the review, replace this notice with a simple note on this article's talk page.(October 2015)
The lower division consists of pale-yellow, current-bedded sand and loam, with layers of pipeclay and occasional beds of flint pebbles. In the London basin, wherever the junction of the Bagshot beds with the London clay is exposed, it is clear that no sharp line can be drawn between these formations. The Lower Bagshot Beds may be observed at Brentwood, Billericay and High Beach in Essex; outliers, capping hills of London clay, occur at Hampstead, Highgate and Harrow. In Surrey, considerable tracts of London clay are covered by heath-bearing Lower Bagshot Beds, as at Weybridge, Aldershot, Woking etc. The Ramsdell clay, N.W. of Basingstoke, belongs to this formation. In the Isle of Wight, the lower division is well exposed at Alum Bay (200 m.) and White Cliff Bay (140 ft.). Here it consists of unfossiliferous sands (white, yellow, brown, crimson and every intermediate shade) and clays with layers of lignite and ferruginous sandstone. Similar beds are visible at Bournemouth and in the neighborhood of Poole, Wareham, Corfe Castle and Studland.[1]
The leaf-bearing clays of Alum Bay and Bournemouth are well known and have yielded a large and interesting series of plant remains, including Eucalyptus, Caesalpinia, Populus, Platanus, Sequoia, Aralia, Polypodium, Osmunda, Nipadites and many others. The clays of this formation are of great value for pottery manufacture; they are extensively mined near Wareham and Corfe, whence they are shipped from Poole and are consequently known as 'Poole clays'. Alum was formerly obtained from the clays of Alum Bay; and the lignites have been used as fuel near Corfe and at Bovey. The Bracklesham Beds are sometimes classed with the overlying Barton clay as Middle Bagshot. In the London basin the Barton Beds are unknown. In Surrey and Berkshire, the Bracklesham Beds are from 20 to 50 ft. thick; in Alum Bay they are 100 ft., with beds of lignite in the lower portion; and about here they are sharply marked off from the Barton clay by a bed of conglomerate formed of flint pebbles. The Upper Bagshot Beds, Barton sand and Barton clay, are from 140 to 200 ft. thick in the Isle of Wight. The Agglestone (or Haggerstone) rock and Puckstone rock, near Studland in Dorset are formed of large indurated masses of the Lower Bagshot beds that have resisted the weather; Creechbarrow near Corfe is another striking feature due to the same beds. Many of the sarsen stones or greywethers of S.E. England have been derived from Bagshot strata.[1]
References
^ abOne or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Bagshot Beds". Encyclopædia Britannica. Vol. 3 (11th ed.). Cambridge University Press. p. 207.
March 24, 2023
bagshot, formation, this, article, largely, based, article, copyright, encyclopædia, britannica, eleventh, edition, which, produced, 1911, should, brought, date, reflect, subsequent, history, scholarship, including, references, when, have, completed, review, r. This article is largely based on an article in the out of copyright Encyclopaedia Britannica Eleventh Edition which was produced in 1911 It should be brought up to date to reflect subsequent history or scholarship including the references if any When you have completed the review replace this notice with a simple note on this article s talk page October 2015 In geology the Bagshot Beds are a series of sands and clays of shallow water origin some being fresh water some marine They belong to the upper Eocene formation of the London and Hampshire basins in England and derive their name from Bagshot Heath in Surrey They are also well developed in Hampshire Berkshire and the Isle of Wight The following divisions are generally accepted Upper Bagshot Beds Barton sand and Barton clay Middle Bagshot Beds Bracklesham Beds Lower Bagshot Beds Bournemouth Beds and Alum Bay Beds Bagshot FormationStratigraphic range Ypresian PreꞒ Ꞓ O S D C P T J K Pg NTypeGeological formationUnit ofBracklesham GroupSub unitsSwinley Clay MemberUnderliesWindlesham FormationOverliesLondon Clay FormationThicknessup to 45 metres 150 ft LithologyPrimarySandOtherClay Silt GravelLocationRegionEuropeCountry UKExtentLondon BasinType sectionNamed forBagshotLocationHeathland near Bagshot The lower division consists of pale yellow current bedded sand and loam with layers of pipeclay and occasional beds of flint pebbles In the London basin wherever the junction of the Bagshot beds with the London clay is exposed it is clear that no sharp line can be drawn between these formations The Lower Bagshot Beds may be observed at Brentwood Billericay and High Beach in Essex outliers capping hills of London clay occur at Hampstead Highgate and Harrow In Surrey considerable tracts of London clay are covered by heath bearing Lower Bagshot Beds as at Weybridge Aldershot Woking etc The Ramsdell clay N W of Basingstoke belongs to this formation In the Isle of Wight the lower division is well exposed at Alum Bay 200 m and White Cliff Bay 140 ft Here it consists of unfossiliferous sands white yellow brown crimson and every intermediate shade and clays with layers of lignite and ferruginous sandstone Similar beds are visible at Bournemouth and in the neighborhood of Poole Wareham Corfe Castle and Studland 1 The leaf bearing clays of Alum Bay and Bournemouth are well known and have yielded a large and interesting series of plant remains including Eucalyptus Caesalpinia Populus Platanus Sequoia Aralia Polypodium Osmunda Nipadites and many others The clays of this formation are of great value for pottery manufacture they are extensively mined near Wareham and Corfe whence they are shipped from Poole and are consequently known as Poole clays Alum was formerly obtained from the clays of Alum Bay and the lignites have been used as fuel near Corfe and at Bovey The Bracklesham Beds are sometimes classed with the overlying Barton clay as Middle Bagshot In the London basin the Barton Beds are unknown In Surrey and Berkshire the Bracklesham Beds are from 20 to 50 ft thick in Alum Bay they are 100 ft with beds of lignite in the lower portion and about here they are sharply marked off from the Barton clay by a bed of conglomerate formed of flint pebbles The Upper Bagshot Beds Barton sand and Barton clay are from 140 to 200 ft thick in the Isle of Wight The Agglestone or Haggerstone rock and Puckstone rock near Studland in Dorset are formed of large indurated masses of the Lower Bagshot beds that have resisted the weather Creechbarrow near Corfe is another striking feature due to the same beds Many of the sarsen stones or greywethers of S E England have been derived from Bagshot strata 1 References Edit a b One or more of the preceding sentences incorporates text from a publication now in the public domain Chisholm Hugh ed 1911 Bagshot Beds Encyclopaedia Britannica Vol 3 11th ed Cambridge University Press p 207 Retrieved from https en wikipedia org w index php title Bagshot Formation amp oldid 1094199843, wikipedia, wiki, book, books, library,
