206 The Rev. W. Conybeare on 



minute grains of iron pyrites. At fifteen yards distance from the 

 dyke the alteration ceases, and the sandstone resumes its usual cha- 

 racter, becoming reddish and destitute of pyrites. Where the dyke 

 traverses the great insulated mass of slate, it is very irregular both 

 in thickness and direction. The works of Gob colliery have reached 

 this dyke 500 yards inland from the face of the cliff: the coal is 

 altered by it to a considerable distance from its point of contact, being 

 reduced to the state of a cinder, which can be employed only for burn- 

 ing lime. This dyke throws out the measures of Gob colliery, which 

 are not recovered on its eastern side : its breadth is about 12 feet 

 where it comes to the surface of the cliff, but varies considerably in 

 different parts of its course. 



Immediately behind Carrick Mawr, an opening may be seen in 

 the cliff which forms the channel of a torrent ; pursuing this inland 

 for the distance of about a mile it is found to issue from a small 

 lake surrounded with basaltic cliffs. We were ourselves prevented 

 from visiting this spot, but from the descriptions we received of it 

 were led to wonder, that none of those who consider this country 

 as volcanic had selected it as a crater. 



At some distance east from Carrick Mawr dyke is the Saltpans 

 dyke, which also throws out the coal of Gob mine on the west ; its 

 breadth is eight yards. Still further is a thin dyke ; both these 

 alter the coal. North Star dyke follows. This is often cut 

 through in the collieries, its breadth is eight yards : it does not 

 shift the coal, but reduces it to cinder for nine feet on each side of 

 its contact. 



Where the cliff declines towards Ballycastle, the coal measures 

 terminate abruptly, and are succeeded by trap rocks. It seems that 

 this position must have been produced by a fault and subsidence. 



Near Ballycastle a broad valley opens into the interior to- 



