220 A POPULAR SKBTGH OK THE 



which the water came in from the surface, and in which, by " dab- 

 bling with a stick/' the whole of the marl would tumble in, leaving 

 a circular hole from two to eight feet in diameter, and extending 

 from the gravel below either to the surface of the ground or to a 

 mass of similar gravel above. It is evident, therefore, that it is to 

 these " pot holes" that the presence of the gravel among the beds of 

 marl is due, the holes either having a previous existence, or being 

 themselves formed by the action of the waters* which brought the 

 gravel into this part of the country. 



The organic remains which may be considered proper to the dilu- 

 vium, are those only of animals living during or just prior to the 

 period when it was formed. Of these, I have not heard of any 

 others but land animals. Remains of these were discovered in the 

 Dream Cave, near Wirksworth, of which the reader will find a 

 description in Dr. Buckland's Reliquiae Diluvictnse. Some bones of 

 the Elephas primigenius, or Mammoth, have likewise been disco- 

 vered in the gravel near Derby, one of which is in the possession of 

 Mr. Fearn of that place. A tusk, and a considerable number of the 

 bones of the same animal were also found at a slight depth below 

 the surface, in the cutting of the railway below Smithimore Bridge, 

 in the valley of the Amber ; but as they were in a very fragile state 

 they were nearly all destroyed by the workmen, from whose sacri- 

 legious hands the remainder were rescued by Mr. Milnes, of Stub- 

 bing Edge, near Ashover. 



We Avill now consider all the superficial matters stripped off, and 

 the regularly bedded rocks exposed to view, the uppermost of which 

 are the rocks belonging to the 



New Red Sandstone System. 



This system or group of rocks is a very remarkable one in the 

 Geology of England. It preserves certain characters throughout its 

 course, almost invariably forming a comparatively level tract of 

 beautifully fertile and well wooded country, its beds being nearly 

 always horizontal, and its colour generally red, The composition, 

 however, and structure of its parts, as also their thickness and 

 extent, vary greatly in different portions of its range. It admits, 



* It is not uncommon in brooks with rocky bottoms, to find small basins 

 containing one or more pebbles, to which a whirling motion is communicated 

 by the action of the current, continually increasing the size and depth of the 

 basin : a similar action may possibly have produced these " pot holes." 



