Mr. Buddle's Notice of a Whin Dyke. 11 



On an old plan of the workings in the Low Main Seam in Montague 

 Main Colliery, in my possession, a " Cinder Dyke" is represented, run- 

 ning in the same direction, and immediately above the line of the Whin 

 Dyke, to which our attention is now directed. 



The Low Main Seam lies about 30 fathoms above the Beaumont 

 Seam, and I have no doubt but the " Cinder Dyke" described in the 

 plan of the Low Main Coal Seam, is the same Dyke which we have found 

 in the Beaumont Seam, as already described, or at least, that the Cinder 

 Dyke is produced by the Whin Dyke below. I have no information as 

 to whether any Whin was observed at this Cinder Dyke in the main 

 coal. It is, therefore, a matter of doubt, whether the Whin extends up- 

 wards, from the Beaumont Seam to the Low Main Seam, or not ; or 

 whether its vertical extent is limited to the space between those two 

 seams, which is about 30 fathoms. 



No traces of the Whin Dyke have ever, to my knowledge, been ob- 

 served on the surface here ; it is, therefore, to be inferred that it does 

 not pass through the whole of the strata, from the depth of the Beau- 

 mont Seam to the surface ; and it is even questionable whether the Whin 

 extends actually up into the Low Main Seam, although the Cinder 

 Dyke, noticed in that seam, is undoubtedly caused by it. The Low 

 Main Seam here lies at about 78 fathoms from the surface, and the 

 Beaumont Seam lies 30 fathoms deeper. 



This Whin Dyke may be said to rest upon the Beaumont Seam, as it 

 does not actually pass through, but merely depresses and thins it, with- 

 out actually coming in contact with the Coal ; as the Black Metal Roof 

 continued above the Coal, in the exploring drift a b {see section), till 

 the upcast was met with : so that, in all probability, the Black Metal and 

 other strata, which line the sides of the Whin Dyke, all interpose between 

 the Coal and the Whin, in a compressed or thinned state, similar to the 

 Coal, as shewn on the diagram. 



As the Whin Dyke does not pass through the Beaumont Seam, we 

 may infer that no traces of it will be found in the seams of Coals which 

 lie below that seam. 



This exhibition of a Whin Dyke shows it to be an exception to the 



