the North-eastern Part of the County of Antrim. 77 



logh Bay, and present the same structure and the same gradations which have 

 been already described (14, 15). The conglomerate covers the coal sand- 

 stone, and is identical with the less coarse varieties of the Cushendall con- 

 glomerate, particularly those of the cliffs in Red Bay, the fragments being 

 as usual quartz and mica slate of various sizes, imbedded in a coarse sandstone 

 of a reddish colour. Both the conglomerate and red sandstone terminate 

 abruptly against the mica slate in the southern corner of the bay. On the 

 northern side, the conglomerate extends under the greenstone of Fairhead, 

 the red sand having previously thinned out. To what distance it ranges in 

 this direction it is impossible to determine, the strata are so completely hidden 

 by subsidences; but it is possible that it soon terminates, since it appears from 

 sections exposed in other places, that the Fairhead greenstone reposes upon 

 the coal sandstone itself. 



(17.) It has been thought that the trap and sandstone alternate here. I 

 could detect no such alternation; and the mistake arose from "^"^ viewing the 

 conglomerate in relation to some subsided masses of greenstone," as has 

 been well remarked by Mr. Conybeare. 



(18.) It may be questioned whether the rock which I have called new con- 

 glomerate, should be separated from the old red sandstone. The facts surely 

 warrant such a separation ; and it may be well to recapitulate them. In our 

 old red sandstone granite or mica slate pebbles never occur, while both are 

 found, the latter most abundantly, in the conglomerate. The conglomerate 

 covers the mica slate and old red sandstone unconformably. The porphyry 

 overlies the old red sandstone, but is covered by the conglomerate : besides, 

 in Red Bay and Murlogh Bay, there is a clear gradation from the conglo- 

 merate into the new red sandstone. 



(19.) This whole series of mechanical deposits with the intrusive rocks, is 

 analogous, in many respects, to the conglomerate and accompanying rocks 

 which occur in South Devon, the theory of whose origin is so well given by 

 Mr. De la Beche in his Geological Manual (pp. 400, 405. 2nd edit.).* 



LAas. 

 (20.) Upon turning the Point of Garron and advancing towards the opening 



* In Dr. Berger's Map, the greater part of our district is coloured as composed of new red 

 sandstone, whereas that formation is of very trifling extent, the mica slate occupying by far the 

 greater portion of the area. In the notes to the coast sections, similar mistakes continually 

 occur. Tea-bulioah and several other mountains are said to " exhibit basalf, chalk, and red sand," 

 while not a particle of red sand is to be met with beyond the limits described. This will appear 

 sufficiently from the details already given. (183C.) 



