Bagshot Formation

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:

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.

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