6 4 o [Proc- B.N.F.C., 



form the valley bottom, under alluvium and drifts, as far as the 

 river, 600 yards to the northward, and was the original floor of 

 the Lower Basalt at a level of 140 to 150 feet above datum. This 

 member of the basaltic series, therefore, must here be little more 

 than 40 to 50 feet thick, where present ; a very different tale from 

 a thickness of some 700 feet of supposed Lower Basalt at Divis, 

 only 7 miles off. The original fall in the surface of the Upper 

 Basalt suggested in the fall westward of the Six-Mile Water 

 implies, moreover, a descent in the Interbasaltic Zone towards the 

 lake, and prepares us for an outcrop of the beds precisely where 

 lignite-beds are reported at the lake-margin. 



Again, on the south side of the valley, the Zone is 655 feet 

 above datum on the east side of Lyle's Hill, against 613 feet on 

 the west side in a distance of some 400 yards. This gives a 

 decline of some 11 feet in 100 yards; in so far as we are justified 

 in drawing an inference from such meagre data — and there is 

 nothing positive against the inference — a descent of such magni- 

 tude would bring Upper Basalt into the large drift-covered tract 

 of Rickamore, west of Lyle's Hill, and an outcrop of the Zone at 

 the lake margin, still further south than the embouchure of the 

 Six-Mile Water. That no records of the Interbasaltic Beds* have 

 been met with in Rickamore is not of great moment as contra 

 evidence, for Prof. Seymour speaks of the dying out of the Zone 

 " towards the north-west end of the Upper Basalt outcrop."! 

 From what I have seen personally, I should say the same 

 circumstances obtain, southward and south-eastward ; so that we 

 are practically without a distinguishing plane, westward and 

 southward, by which to determine whether the basalt beyond 

 Lyle's Hill in those directions is Lower, and not rather — as I 

 believe it to be — Upper. 



*" Inter. Beds," pp. 100, 101. Mining Captain Dryburgh made borings 

 here, in the townland of Claremont, which revealed bole, as well as lignite and 

 lithomarge, as he personally informed me. 



t" Inter. Beds," p. 89. 



