304 Mr. N. Wood on the Geology of Northumberland, S^c, 



arrangement of position. The vale of the Tweed is laid down as New 

 Red Sandstone, the great Limestone deposit is confined to the same limit- 

 ed range, while the extensive moorland district of Northumberland is 

 characterised as thick beds of Grit and Limestone, denominated in the 

 tabular account as Hazel Post, Mountain Limestone, and Post, but 

 distinguished and coloured different from the Mountain Limestone of 

 Alston and Derbyshire, though it is remarked, that " the relative po- 

 sition of this group is not corrrectly ascertained." 



Having had frequent opportunities, in the course of professional 

 practice, of becoming acquainted with the geological position of some 

 of the Coal-beds, associated with the Mountain Limestone of Northum- 

 berland, and having found many reasons for suspecting the accuracy 

 of the views taken by these authorities, I was induced in 1826, to un- 

 dertake an examination of the strata exhibited along the sea coast, from 

 the Tyne to the Tweed, for the purpose of endeavouring to determine 

 the relative position of the different Coal-beds, and more particularly 

 those occurring near the mouth of the Tweed. 



I now offer to the notice of the Society a section of the strata exhibited 

 along the line of the coast, from which, together with an east and west 

 section from the coast at Tynemouth to the New Red Sandstone near 

 Carlisle, and another north and south section across the Stublic Dyke, 

 I shall endeavour to show, 



1. That the regular Coal Measures, which in all the Geological Maps 

 are made to terminate on the west at or near Hedley Fell, stretch in a 

 narrow zone into Cumberland. 



2. That the great central beds of Mountain Limestone contain fre- 

 quent and thick beds of workable Coal ; and that the most extensive 

 deposit of this mineral, below the Millstone Grit, occurs near the bot- 

 tom of the series. 



3. That the Red Sandstone of the Tweed is not referable to the New 

 Red Sandstone conglomerate, as coloured by Greenough, but is a Red 

 Sandstone which underlies the Mountain Limestone and the Coal-beds 

 near the Tweed. 



Section, Plate XXVI., is a bird's-eye view of the strata along the 



