GEOLOGY 



The UPPER ESTUARINE SERIES which enters but little into the 

 surface geology, consists of black, grey, reddish, greenish and bluish clays, 

 with white and brown sands, much like the Lower Estuarine Series. 

 Nail-head spar, a form of calcite, is frequently present. These beds 

 occur at Stoke Goldington and along the borders of the Ouse from 

 Weston Underwood to near Olney, where they are from 15 to 20 feet 

 in thickness. Formerly they were regarded as Upper Lias. 



They have been proved in borings in Salcey Forest, and at Dean- 

 shanger on the Northamptonshire borders, and also at Stony Stratford. 

 To the south-west of that town the Upper Estuarine Series rests directly 

 on the Upper Lias clays, and it may do so near Olney. 



The GREAT OOLITE LIMESTONE consists of white limestones, marls 

 and compact grey limestone. Some layers contain scattered grains of 

 oolite, others are largely oolitic and false-bedded, while some are sandy 

 and minutely current-bedded. The upper beds comprise compact shelly 

 limestone with the gasteropod Nerincea, and with many lamellibranchs 

 such as Cyprina, Astarte, Gervi/fia, etc. Other bands yield corals, Lima 

 cardiiformis, Terebratula maxillata^ and Clypeus. 



The Great Oolite Limestone which extends over much of the 

 northern part of the county forms an undulating well-wooded district. 

 The higher tracts are however largely covered by Boulder Clay : hence 

 there is a mixed soil of chalky clay on which beans and wheat are 

 cultivated, amid other arable tracts of stonebrash and much dairy 

 land. 



Numerous quarries are to be met with from Turweston and Bid- 

 dlesden to Shalstone, in Stowe Park, along the Ouse valley at Water 

 Stratford and Buckingham, at Leckhampstead and onwards by Calverton, 

 Bradwell, Great Linford, Stony Stratford and Wolverton. Some of these 

 quarries are but 10 or 15 feet in depth and many are now disused. 



The stone has been employed for building purposes, but even when 

 well-seasoned before use it is by no means durable, and it is not to be 

 compared with the Great Oolite (Bath stone) of the west of England. 

 The argillaceous nature of the limestone causes the lime to be strong and 

 better adapted for mortar than for agricultural purposes. 



In a pit at Bradwell near Newport Pagnell, beneath the Great 

 Oolite Clay, about 16 feet of Great Oolite Limestone has been exposed, 

 comprising pale earthy, shelly, and oolitic limestones, the lower layers 

 false-bedded and containing veins of selenite. This mineral occurs also 

 in thin seams an inch or two thick between the bands of stone. Most 

 probably it is due to the decomposition of pyrites in the clay above, and 



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