Observations on Phenomena connected with the Deposi- 
tion of Sediment ut the present day in the Estuarp 
of the Dee, and theiy beaying upon oldey Deposits. 
BY A. O. WALKER, F.L.S. 
Read March 19th, 1874. 
NE of the difficulties that strikes the Geologist in our 
district is how to account for the great beds of brick-clay, 
such as you may see by the ticket-platform on the Holyhead 
line near the station, at Saltney, and elsewhere in the neigh- 
bourhood of.Chester. It is, I think, tolerably evident that it 
cannot have been dropped as it now is, by an ice-floe, because it 
is pretty uniform in its character throughout hundreds of acres. 
There is also a strong presumption that it is derived from the 
rocks in its immediate neighbourhood, for its colour is the same 
as the New Red Sandstone. Is it not, therefore, possible, that 
it is the result of the grinding action of some great sheet of Ice 
or Glacier, such as now overspreads the surface of Greenland, 
which ground the Keuper Marls of the Cheshire Hills, previous 
to the last submergence of the land, into red mud? When the 
land then became submerged, this would be washed down by 
the sifting action of the water into the deepest parts of the sea, 
where it would lie comparatively undisturbed. Then there 
would float over it sheets of coast-ice, carrying with them, 
adhering to their underside, pebbles from the shores where they 
had been formed, and these, if the water were tidal, as it pro- 
bably was, would constantly ground on the banks, there melt, 
or drop their stones while still floating, from the gradual 
melting of the ice by the water. That this is no imaginary 
