" Report on the Farm-Prize Competition ofl^l^. 565 



period, found its course and is still continued in that direction — 

 from west to east — the river having cut its way through the 

 boulder-clay and the under-lying Oxford clay to the Cornbrash 

 and Middle Oolite limestones. The large valley of the Ouse 

 thus formed displays a great but variable breadth of gravel and 

 alluvium ; the former being composed of a remarkable variety of 

 sub-angular rock fragments and pebbles, derived chiefly from the 

 Boulder-clay in question. This gravel covers up the fossil bones 

 of the Mammoth and other extinct mammalia, thus indicating 

 the period when certain of these physical changes took place, 

 and the gravel itself is covered by an alluvium, in some parts of 

 considerable thickness and great fertility. 



The river Ouse received, in post-glacial times, large, although 

 probably intermittent, supplies from its extensive watershed ; 

 and the formation of the valley, which was thus gradual, may be 

 traced by the remnants of debris in terraces still left at the higher 

 levels — the gravel being, like that at the lower levels, composed 

 of fragments of igneous and metamorphic rocks, as well as fossils 

 and rock-specimens from the coal-measures, triassic, Jurassic, 

 and cretaceous beds elsewhere. 



If the several strata had preserved their original condition 

 the boundary lines might have been comparatively easy for the 

 observer to detect ; but the subsequent phenomena of the glacial 

 and post-glacial epochs have produced more complicated con- 

 ditions ; and in some parts it is with difficulty that the actual 

 boundary lines can be defined, by reason of the superficial 

 deposits. Nevertheless the changes in the appearance and com- 

 position of the soils in a very short distance from north to 

 south — from Boulder-clay to the Alluvium-covered gravels ; — 

 from the Oxford clay to the Lower Greensand ; — and again 

 to the Gault and heavy Chalk-marl, are very striking and 

 remarkable. 



The farm of Mr. Checkley, at Brogborough, is situated at the 

 southern extremity of the band of Oxford clay, and possesses 

 the usual characteristics of that formation, but the more elevated 

 parts are capped with Boulder-clay, thin in most places, but 

 more pronounced on the mount on which the homestead stands. 

 Many boulders are turned up on the farm, and some of them 

 bear the deep striations which are regarded as the graven prools 

 of their glacial transport. 



The adjacent farm of Mr. T. Crouch, at Lidlington, is situated 

 on the boundary line of the Oxford clay and Lower Greensand, 

 the soils of both being blended somewhat at the junction, so as 

 to make it difficult to discover the boundary ; and the Oxford 

 clay portion has been at an earlier period overlaid by Boulder- 

 clay. The latter has, however, been so much denuded as to be 



