| Popis: |
A few miles east of Oxford the Corallian limestones and sands disappear abruptly, and for a long distance to the east and northeast the whole of the Upper Jurassic Series between the Cornbrash and the Portland Beds consists of clay, with some local rock-beds intercalated here and there. With this disappearance of stone comes a great falling-off in the number of exposures; therefore it is not surprising that, while the Portland and Purbeck Beds of Brill and Aylesbury have attracted much attention, the strata below them have been neglected by geologists. In the Geological-Survey memoir on the Middle and Upper Oolitic rocks of England (1895), Mr. H. B. Woodward ends a brief account of the district between Wheatley and Quainton with the sentence ‘Further research in the district is desirable’ (p. 135). It is as a contribution to this further research that this paper is offered. The eleven years that have passed since that memoir was published have brought some changes to the district. At that time perhaps the most difficult of access of any so near to London, it is now traversed by two main lines of railway, while a third is on the point of being constructed. Large brickfields have been opened up for the supply of London and the residential districts of Buckinghamshire. On the other hand, the closing of small stone- and brick-pits continues, to the sorrow of the geologist. I began the study of the strata below the Portlandian in this district in 1899, and |
