82 THE GEOLOGY OF THE BERWICK COAST LINE 



coal measures proper, which may be said to be typically 

 represented at historic Wallsend. Please understand that 

 when we speak of the carboniferous limestone in a general 

 way, of such and such a town or place being situated on it, 

 the whole series is signified, which comprehends alternating 

 strata of sandstone, limestone, shale, and coal. Thus, a 

 man's property might be described as "on the carboniferous 

 limestone " without, in reality, any limestone being accessible 

 from it at all. Now, along our coast here, we have the 

 carboniferous limestone in its typical aspect ; namely, limestone 

 of different degrees of texture and purity, with characteristic 

 fossils, of which the most noticeable are the coralline 

 Lithostrotion junceum (here is a specimen), and Productus 

 giganteus, a bivalve, which will be laid on the Museum 

 table at our meeting. The limestone varies exceedingly in 

 quality, but the purest is quarried at the Scremerston Lime- 

 works, whose smoke is now visible, which is said to contain 

 95 per cent, of carbonate of lime. 



The sandstones of the series are white, yellow, pink, or 

 red — chiefly reddish — but here I may remark that because 

 a sandstone is old and rerl, it by no means follows that it 

 belongs to the " Old Red," as the Old Red Sandstone is 

 familiarly called. That which will come under notice to-day, 

 as we walk along, belongs to the carboniferous limestone 

 series, much of it exhibiting, in a marked and beautiful 

 degree, the effects of weathering, and of what is called "false 

 bedding"; that means where the layers lie at a different 

 angle to those beneath them in the same block, showing an 

 alteration in the course, depth, and conditions of the river 

 or current during deposition. The walls of Berwick are 

 entirely built of local limestone of good quality, very durable 

 and hard to work, except here and there where sandstone 

 has been used for repairs. 



Now, as regards coal, we have represented two seams, or 

 rather aggregations of seams. First, the Lamberton coal, 



