186 



been captureil liy a " suljsequent " working in tlie same readily 

 eroded strata from the nortli, ■\vliioh before the Ice Ago had 

 captured tlie Swale also. 



Thus 'Sh: F. K. Cowper Reed, to whose essay <jn " The 

 ■CJetjlogical History of the Hirers of East Yorkshire " 1 am much 

 indebted, supposes that the Ure i)assed through the Gilling Gap, 

 and entered the sea at Filey, while the Swale may have gone out 

 at Sealby. The Tees, he thinks, went down the Esk valley, and 

 out to sea beyond Sandsend, for the coast was then further 

 ■eastward. 



This last is tlie case with which we are at present most 

 ■foncenunl. and the view of Mr. Reed is not only highly 

 interesting, Init in all probability correct. The course which the 

 Esk ])iu-sues in relation to the dip of the beds is on any other 

 hypothesis difficult to explaiuj and the existence of the large 

 Kildale Gap unaccountable 



"When the Tees had been captured, the Leven began to work 

 back as an "obsequent " stream in the bed of the old head-stream 

 •of the Esk — part of the original bed of the Tees — and a])parently 

 ■captured its triljutary Warren Beck before the Ice Age. I 

 assisted my friend, Mr. P. F. Kendall, to put down a series of 

 borings in order to ascertain, if possible, whether the capture of 

 Warren Beck had really been etlected before the Ice Age or not ; 

 and with the assistance of my friends, the Rev. J. C. Fowler, 

 F.G.S., and Mr P. Huntington, I have since put down a number 

 of additional borings. Although the problem has not been quite 

 conclusively solved, evidence was obtained rendering it almost 

 ■certain that there was a pre-glacial capture. The alternative was 

 that Warren Beck might have been deflected by glacial agencies. 



Of course, when the so-called " INHocene upheaval " took jjlace, 

 the courses of the streams would in most cases become steeper, 

 the possible exception being where there was folding of the strata. 

 Consequently they would leceive new energy, and would denude 

 at a greatly increased late, for the transporting power is in 

 l)roportion to the sixth jiuwer of the velocity. 



AVhat I have ad\anced so far will, I think, have shown 

 roughly how the materials were accumulated, and how, out of the 

 accumulation, the larger features of Cle\'elanil scenery were 

 fashioned The amount of sea-ero.sion during the post-cretaceous 

 u])lift is not easy to appraise correctly, but ihe evidence in favour 

 of the existence of rivers running from the Pennines to the coa.st 

 tends to show that the central valley l)etween the mountains of 



I 



