NOKTH-WEST OP ENGLAND AXD NOKTH WAXES. 121 



In every case, without an exception that I can remember, other 

 than in the gullies presently to be described, wherever in the neigh- 

 bourhood of Liverpool the covering of Boulder-clay has been re- 

 moved, and the underlying rock has been of a nature capable of 

 receiving and retaining such impressions, I have found it planed and 

 striated. The striations are more or less in the direction of 

 north-west, ranging usually from IN". 40° W. to "N. 15° W-* It cer- 

 tainly seems as if an immense mass of ice had moved continuously 

 over the country ; and though the theory of an ice-sheet radiating 

 from the mountain-districts of Cumberland presents the most feasible 

 explanation, yet it is not without its difficulties ; so that some local 

 geologists are inclined to revert to the iceberg and field-ice theory 

 for an explanation. 



The portions of the rocks that have no cover are weathered, 

 eroded, and worn down to a very considerable extent. But the 

 most interesting feature of which we have proof is that the surface- 

 form of the Drift does not always give an indication of the surface- 

 form of the rock beneath. I have already described the Preglacial 

 valley of the Mersey ; and it is difficult to resist the conclusion that, 

 if we could lay bare the beds below the Irish Sea, we should find a 

 system of river-beds ramifying and uniting into one great river dis- 

 charging into the Atlantic ; and it is quite possible that this may 

 have discharged northwards, between Scotland and Ireland, as there 

 is off the Wigtonshire coast, in the words of Captain Beechy, " a 

 remarkable ditch, upwards of 20 miles long by about a mile only in 

 width, in which the depth is from 400 to 600 feet greater than the 

 general level of the bottom about it." These facts are quite in con- 

 sonance with the relations of the British Isles to the continental 

 area of Europe. We are on the edge of a great plateau ; and every 

 valley and mountain on the western coast of Scotland, where they 

 touch the sea, gives evidence by its outline that the country has 

 been submerged. If we pass over to Norway the same holds good ; 

 every thing points to a former and Preglacial or Glacial greater 

 elevation of the country; for the gullies which I have described 

 cut out of the solid Triassic rocks could have been worn down by 

 naught save snbaerial river-action ; and to get this a very considerably 

 greater elevation must have obtained. It will have been observed 

 that the bottom of the buried gullies, where they have been ex- 

 amined, as at the Bivington Beservoir, on the Yarrow, in the. North 

 Docks and the Bhyl Beservoir, all show the action of running water, 

 not that of ice. 



When I took the Liverpool Geological Society over the North- 

 Dock excavations in 1876, Mr. Lyster, the engineer, drew my atten- 

 tion to the remarkable evidence of water-action on some of the rocks 

 at the bottom sloping towards and flanking the river. 



It has long appeared to me, from the facts 1 have observed, that 

 the period of greatest glaciation was one of considerable elevation. 



* A list of glacial striae found in S.W. Lancashire and in Cheshire is 

 given by Mr. G. H. Morton, F.G.S., in the Proc. of Liverpool Geol. Soc. 1876- 

 77, pp. 292, 293. 



