626 Notices of Memoirs — G. S. Morton. 



greater elevations, several miles from the river, and had consequently 

 been compelled to adopt a new theory, which is, that a great sheet of 

 ice once travelled over this part of the country, from the S.E. towards 

 the N.W. The course of the ice seems to have been only slightly 

 influenced by the inequalities of the ground. It was when the land 

 was higher than it is now, and, consequently, when there was a 

 longer slope towards the Irish Sea. 



The localities exhibiting striated surfaces, were indicated on 

 a map, the most distant being about nine miles from Liverpool. 

 They naturally grouped themselves into six areas, each of which Mr. 

 Morton very carefully described, and they occurred indifferently on 

 the Bunter and Keuper divisions of the Trias. 



Assuming the glaciation of the surface of the rocks around Liver- 

 pool to have occurred before the submergence of the land at the 

 beginning of the Glacial Period, and afterwards covered with Boulder- 

 clay, deposited by icebergs or field-ice, some portions must have been 

 denuded during the subsidence, though the denudation that took 

 place seems to have been inconsiderable. The only alteration in the 

 contour of the land seems to have been the reduced elevation of the 

 low ranges of hills, which traverse the district in the same direction 

 as the ice seems to have done. It is a singular coincidence that the 

 strike of the strata is the same as the supposed course of the ice, and 

 that the form of the ground may be accounted for, either by rain and 

 rivers, or, by the scooping power of ice. The direction of the hard 

 Sandstone ridges, with intervening valleys in the softer strata, would 

 support either conclusion. 



Finally, there was little doubt that the country around Liverpool 

 was once covered by a great ice-sheet, at a time when the land was 

 some hundreds of feet higher than it is now, and that it afterwards 

 subsided beneath the sea, when floating ice brought from the hills 

 of the lake district and Scotland debris, which became scattered over 

 the ice-grooved rocks in the form of Boulder-clay. 



II. — On the Mountain Limestone of Flintshike and part op 

 Denbighshiee.^ 



By G. H. Morton, F.G.S., etc. 



ME. Morton pointed out that in Flintshire, within fifteen miles 

 from Liverpool, there is a prominent ridge of Carboniferous or 

 Mountain Limestone. It extends continuously from Prestatyn on 

 the coast of Wales to Llandegla, a few miles north of Llangollen, 

 the distance being twenty-one miles, and the strike of the limestone 

 N. by S.E. and S. Instead of a general description of the forma- 

 tion, he had selected what appeared to be the four most favourable 

 localities as centres of observation : Mold, Holywell, Newmarket 

 (Flintshire), and Llangollen. He alluded to the country around or 



^ Read before the Britisli Association (Section C.) at Liverpool, September, 1870. 

 See also a paper on the Millstone Grit of the North Wales Border, by D. C. Davies, 

 Geological Magazine, Vol. VII., 1870, pp. 68, 122.— Edit. 



