294 W00DRUFFE-PEAC0CK : NATURALISTS AT BOURNE. 



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and breaks up (prov. brashy) for the cornland. To the north of 

 Bourne this formation occurs as patches or inliers that are 

 surrounded by Oxford clays. Morton and Hanthorpe are built on 

 one of these cornbrash islands. Three-quarters of a mile westward 

 of the church, there are two exposures of the cornbrash bed that are 

 known as the Old Town Pit and the New Town Pit. Another is 

 situated about half a mile from the town, just to the north of the 

 Bourne Drove. Diagrammatic sections of these, prepared by Mr. 

 Davies, were shown. In each of these cuttings the cornbrash and 

 superincumbent layers of post-glacial clays and gravels are well 

 developed, and the contained fossils are, as a rule, numerous and 

 well preserved. These fossils include various species of Ammonites, 

 Gervillia^ Lima, Ostrea, Pecten, Pholadomya, Trigonia, etc. The 

 Oxford clays, upon which the greater portion of the town is built, 

 constitute one of the predominant geological features of Lincoln- 

 shire. These clays underlie the Fenland ; but, though they attain 

 their maximum development in and around Lincoln, towards Bourne 

 they thin out laterally and disappear to the north and east beneath 

 the clays and gravels of the Fenland. The Oxford clay, a deep-sea 

 deposit, is extremely fossiliferous, abounding in Ammonites and 

 Belemnites. In the vicinity of Bourne it graduates into a shelly, 

 concretionary limestone known as Kellaways rock. One of the 

 most interesting pits in this formation lies about a mile to the north 

 of Bourne. The characteristic fossils are Bekmnites <m*enii, Aviada 

 expansa, and Grypluza bilobata. Eastward of the town stretches the 

 Lincolnshire Fenland, with its post-glacial beds of marine silts and 

 clays, and inter-stratified layers of peat. The Fenland represents 

 a plain of marine denudation, on which has been built up, by marine 

 agencies, the present integument of silts, clays, and peats. The 

 operation of waves, tides, and currents, extending over great periods 

 of time, has been the main factor in its formation. The peat beds 

 which are exposed in most of the drains offer themselves as interest- 

 ing object lessons to the geologist. They point to a time when 

 forest trees and other vegetation flourished in rank luxuriance in the 

 district. These trees are frequently found in ploughing ; their over- 

 lying beds of silt and clay, often containing sea-shells, suggest the 

 inundations that first destroyed, and afterwards buried, them. Of 

 the antiquity of these there can be no doubt. The remains of 

 neolithic man, consisting of barbed arrow-heads, celts, and dug-out 

 canoes have been discovered at several localities in the vicinity of 

 Bourne. 



Mr. A. E. Wherry and Mr. J. J. Davies supplemented the above 

 valuable and interesting description by indicating the local boundaries 



NaturalUr, 



