Correspondence — Ilr. G. H. Morton. 431 



and Mr. Shone stated that the percolation of water along the sand, 

 towards the sti'eamlets, had caused a subsidence of the clay to the 

 amount of thirty feet. Not having seen the section I can give no 

 definite opinion upon it, but in the paper referred to Mr. Shone 

 endeavours to explain the subsidence of the Peat and Forest-beds 

 at Ince, on the south shore of the Mersey, and on the west coast of 

 England, as having been caused by the subterranean erosion or 

 denudation of the underlying beds. 



Mr. Shone gives the section of the Peat and Forest-beds from 

 Ellesmere Port to Ince Ferry from my recently published " Geology 

 of the Country around Liverpool," and assumes that the four basin- 

 like depressions along the Manchester Ship Canal were caused by 

 subterranean erosion and not by the deposition of silt and the growtla 

 of peat between ridges of sandstone. I do not, however, see that 

 this theory can be satisfactorily applied to the post-Glacial beds 

 referred to, for all the conditions are very different to those at 

 Upton. It does not seem to be a logical conclusion to assume that 

 because subterranean erosion occurs at Upton in consequence of a 

 bed of sand underlying the Boulder-clay that it also occurs at Ince, 

 in consequence of beds of grey silt and stiff clay underlying the 

 Peat and Forest-beds. Mr. Shone refers to a bed of sand between 

 the Boulder-clay and the post-Glacial beds at Ince ; but it is quite 

 a local deposit and changes to a grey clay within about 100 yards, 

 and there is no such sand at Stanlow and Ellesmere, where the 

 same amount of subsidence is shown. It does not seem possible 

 that the beds of stiff clay could have been eroded beneath the 

 surface under an area of several square miles of country, not only 

 about Ince, but in other similar areas near Liverpool. 



Mr. Shone's theory is, however, not original in connection with the 

 district, for in 1854 the late Mr. John Cunningham, F.G.S., brought 

 it before the British Association, and, so recently as 1887, in a paper 

 read before the Liverpool Geological Society, and published in the 

 Proceedings, on the " Stanlow, Ince, and Frodshara Mai'shes," I 

 attributed the sinking of the land for about fifty yai'ds along the 

 edge of the Marshes to the influence of water from the river on 

 a bed of sand underlying the grey clay and Peat and Forest-beds, 

 but I afterwards found that the sand was not persistent, and that the 

 slope of the land towards the Mersey was probably the original 

 form of the ground. According to Mr. Shone's theory the surface 

 of the land should fall rapidly along the edge of the Gowy and 

 other streams, but I have seen no such subsidence. 



Several instances have been described where the Peat and Forest- 

 beds occurred on the Bunter Sandstone, many feet below the range 

 of the tides. About Ince these beds rest on the rock in many places, 

 and at various elevations. Along the shore on the north of the 

 line of section the Peat and Forest-bed, with the trunks of trees, 

 was seen resting on the Boulder-clay, and at the distance of a few 

 yards on the rock. 



The Boulder-clay rests on sand in cliff sections in many places 

 around Liverpool, but I have never seen such an instance of 

 subsidence caused by subterranean erosion as that described by 



