Daley, B. & Balson, P. 1999. British Tertiary Stratigraphy. Geological Conservation Review Series No. 15, JNCC, Peterborough, ISBN 1 86107 469 7.
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B. Daley
The Palaeogene strata to the west of London range from the Upnor Formation and Reading Formation of the Lambeth Group, formerly the Woolwich and Reading Formation, through the Tilehurst Member' of the Harwich Formation and the London Clay to the Virginia Water Formation and the younger strata still referred to as the 'Bagshot Beds'. At one time, the areal extent of the Palaeogene was considerably greater than at present. Remnants of this wider development are to be found in the many outliers on the Chalk of the Chiltern Hills
Exposures are now few in number. Three stratigraphically significant Palaeogene sites in the area are included in tne GCR. The junction with the Chalk, together with a thin sequence of marine and fluvial Lambeth Group strata can be examined at Pincent's Kiln. At Harefield, a slightly thicker sequence includes fossiliferous basal London Clay, whilst at Bolter End an unusual pebble suite in the Reading Formation provides some insight into the nature of the contemporary hinterland. The GCR site at Cold Ash Quarry, near Newbury, is predominantly a fossil plant site and is covered in the Mesozoic to Tertiary Palaeobotany GCR volume (Cleal and Thomas, in prep.).
In the site descriptions below, following the usage by earlier workers, some traditional stratigraphical terminology is used in addition to that recently introduced by Ellison et al. (1994).