NOTES AND QUERIES. 



117 



tiou between the two being sharply and clearly defined, (vide right hand side of 

 the sketch). 



The cutting afforded by this quarry shows that the basalt, the ancient chalk- 

 drift, and the chalk itself, have been denuded ; and a layer of dark brown clay, 

 formed apparently exclusively of disintegrated basalt, spread over all to the 

 depth of eight feet. 



The surface of the chalk beneath its ancient flint drift, as well as the more 

 recent basalt clay deposit, has been worn into hollows and cavities of variable 

 width and depth ; ana in those filled by the basalt clay, the quarrymen frequently 

 find the fragments of deer's horns and bones. (See left hand side of sketch at 

 b 3 b). 



With regard to the probable age of this drift basalt clay, there are some who 

 may probably suppose that it is comparatively recent ; and the product of rain 

 and snow wearing away and washing down the basalt from the higher lauds of 

 the mountain on to its flanks. Such would be a hasty conclusion. Rain 

 acting on disintegrating rock does not deposit its sediment, or fine detritus, on 

 the flanks of hills ; but carries them by the floating power and velocity of its 

 waters to the lowest lands of the plains, and eventually to the bed of the ocean. 

 If that was the origin of the deposit, its formation should be still progressing ; 

 but it is very evident that the contrary is the case. 



On carefully studying the facts presented to us in this quarry, it is clear that 

 the era of the last great denudation was drawing to a close before the formation 

 of this basalt clay, which must have been deposited as mud at the bottom of 

 possibly a shallow sea or estuary. It belongs therefore to the Glacial or Escar 

 Drift, which bears the same relation to the other rocks as this clay does to those 

 beneath it. The horns of the deer, and bones of the same animal, or of others, 

 may have been washed into the sea, and swept by tides and currents on to this 

 bank of silt, through which they sunk till they rested on the surface of the 

 chalk beneath. 



If this supposition be true, and I see no reason to question its correctness, 

 we have evidence here to show that deer, and very possible other animals, 

 existed in these latitudes, while the land presented a very different configuration 

 to that which it now has ; and a large portion of what is now the north of Ire- 

 land was more than seven hundred feet lower than at present, and therefore sub- 

 merged beneath the level of the sea. — Truly yours, Geo. V. Du Noyer, Dublin. 



DlTHYROCARIAN CRUSTACEAN REMAINS AT PORTMADOC. SlR, Allow me to 



inform your readers that the " New Crustacean form allied to Dithyrocarus," 

 referred to in your last number, page 74, occurs in this neighbourhood (Port- 

 madoc), and has recently been collected by me from the lower Lingula beds at 

 Wern. 



My specimen is the exact size of your woodcut, which is rather larger than 

 the Skiddaw specimens lately sent me by Mr. Gregory, of 3, King William Street, 

 Strand, who has, I understand, some very fine examples. — 1 am, Sir, yours 

 obediently, John Ash, Portmadoc. 



Curious Geological Pact. — In a field, the property of Mr. Renton, situate 

 a short distance from the point where the Leeds and Liverpool Canal is crossed 

 by the Midland Company's railway, at Idle, near Bradford, is a considerable 

 hill, or piece of rising ground, which has been noticed to be gradually attaining 

 greater elevation during a period extending over the last thirty years. There 

 are even young men who remember the field being quite level, whereas now 

 there is a mound near the middle of it. The cause of this singular elevation 

 has given rise to much speculation. Some persons suppose that it is owing to 

 the upward pressure of water in the bowels of the earth. — Times," Nov. 22, 

 1860. What does this mean? — Querist. 



We do not know the hill referred to, but we should think from the above 



