120 



MR. E. W. BINNEY ON A MINERAL VEIN 



the main joints of the rock, parallel to the fissure, are also 

 traversed by such veins. The chief dip of the stone in the 

 quarry, although now nearly obliterated and difficult to deter- 

 mine, owing to the vertical cleavings of the stone, was found 

 to make an angle of 1&° to the north-west. The cleft has 

 evidently been made since the strata were elevated to their 

 present inclination; for on its north side the rock dips to the 

 S.S.E., at an angle of 20°, but on the south side it dips to 

 the N.N.W., at an angle of IP; thus showing an anticlinal 

 axis differing from the main dip of the quarry. 



From the parting of shale in the rock, 4^ inches thick, 

 marked a in the woodcuts, there has since been a heave of 

 the strata of about 3 feet 4 inches; this bed, on the north- 

 west side, being that height above the same deposit on the 

 south-east side. Where the vein comes in contact with the 

 bed of shale, the latter has been converted into a stone some- 

 what resembling greywacke in appearance. 



The sandstone rock, from the fragments of coal plants 

 found in it, was no doubt deposited from water ; and although 

 it does not now present the laminated structure which is so 

 characteristic of the rough rock series, and which so clearly 

 indicates the mode in which those beds were formed, still it 

 is evident that, before the production of the vein, it was 



nothing more than a com- 



mon sandstone. As is 

 usual in all sedimentary 

 deposits, it would have 

 two lines of fracture, one 

 along the lines of depo- 

 * sition, and the other at 

 right angles to those lines. 

 These are known amongst 

 stone masons as the bed- 



then found that the vein of barytes, on being worked more to the north, 

 showed that it divided into two parts, as described in the above woodcut. 



