314 Mr. N. Wood on the Geology of Northumberland, 8Cc. 



of the various beds throughout the coast district, I shall proceed to 

 take a rapid glance at, the probable succession of those beds, exhibited 

 along this line of Section. 



At the mouth of the Tyne, the I'egular Coal Measures are found un- 

 derlying the cap of the Magnesian Limestone, at Tynemouth. In 

 general, the Coal and softer beds of Shale, &c. not having withstood 

 the action of the sea, are all denuded and covered with sand ; but where- 

 ever the rocks have withstood the waves, we find, from the Tyne to the 

 Coquet, those rocks are all referable to the regular Coal Measures. 

 The workings of the different Coal Pits, and the various trials for Coal 

 along this line, might also be adduced in corroboration of this opinion. 

 How far beyond the Coquet, or if so far down in the series of these 

 Measures, workable beds of Coal may exist, cannot, from an examina- 

 tion of the coast strata, be determined ; but when we reach Alemouth 

 we are certain of having passed the boundary of the Coal formation. 



A series of Gritty Sandstones, with their accompanying Shales then 

 occur, underlying the Coal Measures, which agree in character, as well 

 as in position, with the " Millstone Grit," which reaches to near Howick. 

 Messrs. Conybeaee and Phillips terminate this class at the second or 

 third Limestone Bed. If we adopt this classification, the northern ex- 

 tremity of this suite of rocks would therefore be about Boulmer Point. 



We then find thick beds of Limestone rising from underneath the 

 preceding Grit Rocks, corresponding with what is called by Conybeare 

 and Phillips, " the great central deposit of Limestone." Passing the 

 mass of Basalt between Howick and Dunstanburgh, which appears to 

 be identical with the Whin Sill of the Lead Mine district, we have ten 

 or eleven beds of Limestone bassetting out to the north, resting on, and 

 terminated by a thick bed of Red Ferruginous Sandstone, at Sunder- 

 land, which, though a considerable way down in the series, does not 

 appear so low as the Red Sandstones at the mouth ot the Tweed. North 

 of Sunderland, the beds are thrown down, and taking a contrary dip, 

 the Basalt is again found at Bamburgh. From this place the strata rise 

 north, and we again pass over the great central beds of Limestone, 

 which axe terminated by, and rest on, the thick beds of Red Sandstone, 



