334< Mr. N. Wood on the Geology of Northumberland, ^c. 



A question naturally arises, why we do not, throughout the whole 

 range from the west, along the base of the transition hills, find in the 

 lower beds of the series such seams of Coal as those of Scremerston. 

 The only beds which appear at all equivalent to those of Berwick, being 

 the Coal found on the Esk, and near the head of the North Tyne. It 

 must, however, be observed, that in no place throughout the whole extent 

 of the range, do we find so extended a plain near the bottom of the series 

 as that of the Tweed ; and in few places do we descend so low down in 

 the series, except close to the base of the transition hills, where we find 

 the strata much broken or distorted, and the inclination often consi- 

 derable. 



That this expanding or flattening out of the strata, in the Mountain 

 Limestone, has some effect upon the beds of Coal has been previously 

 noticed, and may be proved by tracing some of the beds in their range 

 eastward, where the strata become flat ; Coal Sills, which, in the high 

 and mountainous district of Alston Moor, exhibit only traces of Coal, 

 furnish thick and workable beds in the comparatively flat and extended 

 country to the eastward. 



In conclusion, it appears, therefore, that the lower beds of the 

 Mountain Limestone, in the north eastern parts of Northumberland, 

 contain several beds of workable Coal, below the great central beds of 

 Limestone, and that these Coal seams rest upon thick beds of Red Fer- 

 ruginous Sandstone, distinct in character from the old Red Sandstone, 

 but which they probably overlie ; as in some parts of the base of the 

 Grauwacke hills of the Cheviot and Scotland, we find conglomerates 

 resembling the old Red Sandstone rising out from underneath the 

 Mountain Limestone, and Ferruginous Sandstone. 



