NORTH-WEST OF ENGLAND AND NORTH WALES. 107 



persistent and regular bands of sand, C, lying upon and concentric 

 with an arch of Boulder-clay, D ; curving upwards further to the 

 south, the two lower bands pass concentrically over another, larger 

 arch of Boulder-clay, E, which becomes very stony. Eventually, 

 after running a distance of over three quarters of a mile, the bands 

 die out at E, as the arch dies into the shore. Erom the point 

 where the intercalated beds of sand unite with the two bands lying 

 on the Boulder-clay arch, the sands and gravels G set in, and 

 increase in. thickness ; as we go south they pass over another length 

 of this lower clay, H, which disappears towards Glynn, leaving only 

 the sands and gravels some 28 feet thick. The upper part of the 

 cliff consists of a continuous sheet of Boulder- clay, I, of a character 

 less stony than that at the base. The greatest height of the cliff is 

 about 60 feet. 



It is interesting to compare this section, which I can certify as 

 accurate for the time, with that given by the late Mr. Binney, E.E.S., 

 20 years earlier *. Mr. Binney states that the cliff wastes away on 

 the average one yard every year. If this be correct, the section I 

 have given may be taken as 20 yards further into the cliff than Bin- 

 ney's, and approximately parallel to it : yet it is very different ; for at 

 Gynn, in his section, the sands and gravels have died into the shore, 

 and the cliff is entirely of Boulder-clay, whereas when I saw it 

 there were about 30 feet of sands and gravels. Neither have the 

 sands and gravels a general dip southwards such as Binney shows. 



If, then, the sands and gravels vary so much in such a short 

 distance, can we assume that they are conterminous with the sands 

 and gravels of the Bibble above Preston, 15 miles off in a direct 

 line, and situated in a drainage-basin of 720 square miles ? 



Eor the time it was written, I consider Mr. Binney's description a 

 very excellent one, though I think he would hardly, if he were 

 now living, maintain that earth-movements had produced the arches 

 of silt then to be seen. 



The lower clay, E, underlying the sands and gravels is harder 

 than that above, standing in places vertically. It contains more 

 stones ; and these are stated to be (though 1 did not verify it) mostly 

 scratched. Comparing the proportion of the various rocks composing 

 them, as given by Binney, with those at Crosby as ascertained by 

 myself, I find that at Crosby there are fewer Silurians and slates, 

 and more granite and igneous rocks ; but the comparison, after all, 

 may be fallacious in this particular. In other respects the nature 

 of the stones is very similar ; but if Mr. Binney was 6orrect in 

 saying that in places the clay was one third stones, the prepon- 

 derance of stones in quantity is very marked, as at Crosby the 

 highest proportion measured by me was 1 to 130 f . Mr. Binney's 



* " Notes on the Drift-deposits found near Blackpool," Memoirs of the Lit. 

 and Phil. Soc. of Manchester, vol. x. Session 1851-52. 



t This is of hand-picked stones ; if we include fine gravel that can he 

 separated by washing, the proportion of stony material will be very much 

 larger. (See Mr. Robertson's report appended.) 



