466 On the Agricultural Geology of England and JVales. 



well as on the elevated table-lands which flank the course of the 

 Evenlode above Oxford — that the excavation of the valleys of the 

 Evenlode and Thames was subsequent to the deposit of this 

 gravel, and caused by the retiring waters of the most recent de- 

 luge that has devastated the earth. 



This argument for the recent origin of the valley of the 

 Thames is of equal force now, when we possess better information 

 respecting the nature of these deposits, if for the expression, retir- 

 ing diluvian vraters, we substitute that of denuding process during 

 elevation. 



The occurrence of pebbles of the red chalk, in the quartzose 

 gravel near Shipston on Stour, and Moreton in the Marsh, has 

 been mentioned as indicating the meeting of a stream of drift 

 from the north-west with another from the north-east. The 

 northern part of the course of the latter was described by the 

 Dean of LlandafP,* in a communication to Dr. Buckland, under 

 the title of gravel of the midland counties in Rutland, Leicester, 

 and Buckinghamshire. It extends, he says, over the plains at the 

 base of the great oolitic chain, and also between those hills and 

 the south-west escarpment of the chalk in Bedfordshire, Buck- 

 inghamshire, and Hertfordshire, but is most abundant in the 

 former position, having a depth of many fathoms^ completely con- 

 cealing the subjacent strata, and sometimes constituting decided 

 hills. Such tracts of gravel are described as abundant on the 

 borders of Rutland, Warwickshire, and Leicestershire. From 

 Houghton on the Hill, near Leicester, by Market Harborough 

 and Lutterworth, to Bramston, near Daventry, continuous beds of 

 gravel extend for forty miles. Near Hinckley a great deposit of 

 gravel, connected with this mass, affords pebbles containing spe- 

 cimens of the organic remains of most of the secondary strata of 

 Britain. It may be traced continuously to that of Shipston on 

 Stour. Most of the hillocks scattered over the lias and red marl 

 between Southam and Shipston are covered with this gravel, con- 

 taining pebbles of all ages ; flints from the chalk, rounded pebbles 

 of hard chalk, and fragments of the different oolitic rocks pre- 

 dominate in Leicestershire : next in abundance to these are the 

 pebbles of granular quartz, resembling that of the Lickey, with 

 others of vvhite quartz, and dark-coloured flinty slate. 



On the west of Market Harborough it would not be difficult to 

 form an almost complete collection of geological specimens of the 

 whole series of English rocks from among these rounded frag- 

 ments, which often occur in boulders of very considerable size. 



The gravel-beds in the low grounds between the oolitic and 

 chalk ridges, and along the valley of B uckingham and Bedford, and 



* In the volume of the Geol. Trans, cited above. 



