Geological Society. 63 



Each of these valleys is separately described, and the general fea- 

 tures of denudation presented by the Cotteswold chain are pointed 

 out ; these, it is asserted, bear traces of the most violent action, and 

 they are contrasted with the state of repose which has evidently pre- 

 vailed in the same districts from the period to which our earliest 

 historical monuments ascend. In the most exposed situations, and 

 those which appear to have suffered most from the action of the de- 

 nuding causes, earth works of British and Roman antiquity are fre- 

 quently found, attesting by their perfect preservation that the form 

 of the surface has remained unaltered since the time of their con- 

 struction. The drainage of the atmospherical waters has here produced 

 no sensible effect for more than fifteen centuries : it is inferred, 

 therefore, that to assign to this cause the excavation of the adjoining 

 valleys, 600 or 700 feet deep, is to ascribe to it an agency for which 

 we have no evidence j the evidence, indeed, as far as it can be ex- 

 amined, being adverse. 



The disposition of the water-worn debris drifted against the Cot- 

 teswold chain and through the breaches opened in it, is also examined; 

 much of it is shown to be derived from rocks situated to the north 

 of the valley of the Warwickshire Avon, and completely cut off by 

 that valley from the Cotteswold district. It is contended that pebbles 

 of this origin can never have been transported by the actual streams, 

 because the drainage of these streams is, and always must have been, 

 from the escarpment of the Cotteswolds to the valley of Avon ; 

 whereas the course of the pebbles is directly opposite, viz. across 

 the Avon, and thence to that escarpment and through its breaches. 

 The valley of Shipston on Stour, which is described as a species of 

 bay in the escarpment of the Cotteswolds, is stated to contain the 

 most remarkable instance of this disposition. 



II. The river collected from these head-waters flows through the plain 

 of Oxford, which is covered to a great extent by water-worn debris ; 

 these are diffused over situations inaccessible to the present floods, and 

 if produced by the actual streams, we must suppose that thev have re- 

 peatedly changed their channel so as to have flowed successively over 

 every portion of the plain where these debris are now found: the oldest 

 historical monuments attest, however, the permanence of the actual 

 channels, and the floods at present bring down no pebbles whatsoever. 



On the south of the plain of Oxford the progress of the river is op- 

 posed by a chain of hills, called by the author the Oxford chain ; 

 this is passed by a defile broken through it. Were that defile closed* 

 an extensive lake would be formed above Oxford, and tlie waters 

 turned into the valley of the Ouse ; by which they would empty them- 

 selves into the aestuary of the Wash. 



The author inquires how this configuration of the valleys could 

 have been produced on the fluvialist theory : he argues, that if the 

 Oxford chain originally (as at present) formed a barrier of superior 

 elevation to the trad intervening between itself and tiie Cotteswolds, 

 that biirricr must have turned all the drainage of the Cotteswolds into 

 the vale of Ouse; under those circumstances the crest of the Oxford 

 chain could never have been eroded by waters which would have 



flowed 



