A HISTORY OF BERKSHIRE 



The urchins Echinocorys vu/garis and Micraster cor-anguinum are to 

 be found in most pits in the Upper Chalk and also often occur in flints 

 in the gravels. All the fossils of the Chalk are marine. Windsor Castle 

 stands upon a mound of Chalk which is believed to be an inlier, 1 that is 

 to say the Chalk projects through the Eocene Beds, and Mr. H. B. 

 Woodward tells me it may be seen in the ice-house in the Castle 

 grounds ; the relations of the formations are however greatly obscured 

 by a thick covering of gravel and alluvium. 



Chalk has been extensively used as a building stone, and many 

 churches are at least partially built of it. Mr. Whitaker remarks that 

 in some old churches, as at Tilehurst and Sonning near Reading, there 

 may be seen a variety of chalk with irregular veins of a dusky tint as in 

 many marbles. He adds that he had not met with it in any section. 8 



Chalk is also used as a dressing for the clay soils, and many of the 

 pits in the county have been worked mainly for that purpose. It is the 

 great water-bearing formation of all the counties round London, and the 

 water is almost invariably colourless, palatable and brilliantly clear. 3 



The full thickness of the Chalk is not found in Berkshire, possibly 

 the highest beds were not deposited over this area, certainly great 

 denudation took place before the time of the Reading Beds, the next 

 over-lying formation in the district. 



In fact there is here a very great break in the geological succession 

 and a considerable series of strata occur in Denmark, Belgium and 

 France, and even in other parts of England, which are absent here. 



READING BEDS 



The Reading Beds are the oldest Eocene formation in Berkshire ; 

 there are however older members of that series in other places, for not 

 only the top of the Cretaceous but also the bottom of the Eocene is 

 wanting here. The Calcaire de Mons of Belgium and the Thanet Sands 

 of Kent and Surrey, for instance, are older Eocene formations than any 

 we have in this county. Hence the Reading Beds lie upon a very 

 greatly eroded surface of Chalk. 



A band of Reading Beds crosses the flat ground from Bray by 

 White Waltham and St. Lawrence Waltham to Twyford, and then turns 

 by way of Sonning to Reading. Most of the town between the London 

 Road and Southern Hill stands on them as does Coley and the higher 

 part of Castle Ward. 



The plateau of Tilehurst is formed of this formation with a capping 

 of London Clay and gravel. 



A strip of Reading Beds runs along the sides of the hills by Engle- 

 field, Bradfield, Bucklebury, and spreads out to some width at Oare. 

 The bottom of the Kennet valley below the alluvium and gravel is 

 mainly formed of Reading Beds from Theale to Newbury, from which 



1 W. Whitaker, 'The Geology of London,' Geol. Survey (1889), i. 176. 

 8 'Geology of Parts of Oxford and Berks,' Geol. Survey (1861), p. 22. 

 3 'The Water Supply of Berks,' Geol. Survey (1902). 



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