72 Mr. Bryce on the Geological Structure of 



down and afterwards recomposed ; or that a preexisting rock of very similar 

 structure has been entirely worn away in supplying materials for this great 

 mechanical deposit. I have observed no pebbles of granite or mica slate. 

 The largest of the fragments are identical with the base itself, while those 

 of quartz are by far the most numerous. In most of the strata the fragments 

 are few : they are rare in those adjoining the mica slate, while they occur in 

 greater quantity and variety in those in contact with the newer conglomerate. 

 Many of the strata, however, include no fragments, and in others they are col- 

 lected into distinct groups in different parts of the same stratum, the remaining 

 portion being quite free from them. The rock, moreover, often loses its coarse- 

 grained gritty structure, and assumes a fine-grained sandy texture, like a grey 

 freestone ; but by far the greater part possesses the appearance and structure 

 formerly described. A sandstone occurs under low-water mark, in advance 

 of the cliffs near the collieries at Bonnycastle. It is overlaid by the carboni- 

 ferous limestone, and must therefore be the old red sandstone. 



(7.) This rock extends from Cushendun to the head of Ballyeemin glen, occupying the greater 

 part of Cross-slieve, tlie upper portion of the glen in which Cushendall is situated, the lower part 

 of the southern side and the greater portion of the bottom of Ballyeemin glen, also the whole 

 southern declivity and half the table-land of the summit of the ridge which forms the northern 

 side of that glen ; the rest of the summit and the whole northern front being composed of mica 

 slate, which seems to constitute the greater part of the ridge, as the covering of sandstone is very 

 thin along the southern side. In the eastern face of this ridge, in the town-land of Tavnagharry, 

 the mica slate protrudes from beneath the sandstone and occupies a small gulf-shaped area, sur- 

 rounded by the sandstone on all sides except the north, where it is joined by a narrow neck, or 

 isthmus, to the great body of the same rock. The Ballyeemin river crosses the southern part of 

 this area ; and the mica slate is seen in the bed of the river, overlaid, on the left bank, by the sand- 

 stone. In the bed and banks of the same river, near the head of the glen, two isolated patches of 

 mica slate are met with, separated from one another by beds of sandstone of small extent, and 

 are probably portions of the rock elevated above the general level, and from which the sandstone, 

 having nearly thinned out in this part, has been worn away. The intervening beds of sandstone 

 seem to occupy a trough or basin between these two projecting peaks or spires of mica slate. The 

 newer conglomerate, which will be immediately described, and which here contains enormous 

 masses of mica slate, reposes immediately on the mica slate forming the upper of these two iso- 

 lated portions, the old red sandstone being most probably overlapped, or having thinned out. 



(8.) Over all the area occupied by the old red sandstone, the strata dip uni- 

 formly to the east. The angle of inclination, however, varies, being generally 

 about 40°, and rarely less than 25°. Near the mica slate it is high and con- 

 formable to that rock, while at points remote from the schist it is less. 



