the North East of Ireland, 203 



basalt. It is highly desirable that the slopes of these hills should 

 be carefully explored ; by examining the channels furrowed in their - 

 sides by the wintry torrents, we might hope to ascertain the whole 

 series of rocks here intervening between the primitive formations 

 and chalk. 



Murloch bay is bounded on the south by a promontory, which 

 exhibits in the cliffs at its base beds of mica slate dipping towards 

 the north-west under an angle of 45° ; but immense slopes of debris 

 (consisting mostly of primitive rocks) interfere to prevent the pos- 

 sibility of determining the structure of the lower regions of the 

 cliff as soon as the bay is entered. Above these slopes red sandstone 

 is seen supporting chalk ; the former rock attains the elevation of 

 560 feet above the beach, the latter extends to the summit of 

 the cliff about one hundred feet higher : between the red sand and 

 the chalk a thin bed of green sand, cementing quartzose pebbles, 

 may be traced. The bed of wacke here occurring in the chalk, 

 has been noticed, pagel73, and several whin dykes are observable.tra- 

 versing the red sand. The most remarkable objects on the beach are 

 a large basaltic dyke, which rises in a projecting crag j and 

 still further to the north, near the centre of the bay, the detached 

 conical mount of Drimnakill, which is formed by a vast subsided 

 mass of columnar greenstone, the columns being thrown con- 

 fusedly together in every possible direction. Near the whin dyke a 

 conglomerate, resembling that of Cushendon, may be seen ; so 

 that this rock appears on either side to skirt the primitive forma- 

 tions of Cushleak. 



Beyond the mount of Drimnakill, the lower parts of the cliffs 

 are still concealed by slopes of debris, among which subsided masses 

 of columnar greenstone form the prevailing feature ; and near this 



2 c 2 



