638 l pn ? c - B.N.F.C, 



The Zone also crops out near the summit of Craignashoke,* 

 where lignite has been excavated ;f but the Lower Basalt being 

 there entirely absent, and therefore no lithomarge or bole existing 

 at this point, the lignite and haematite are the only representatives 

 of the Zone. It may here be explained that "Zone" is hence- 

 forth used in this paper in a general, not in the precise sense, 

 being a convenient term to express an approximate horizon, 

 which, under the circumstances, may represent the period of some 

 upper outpourings of the Lower Basalt, and that of some lower 

 outpourings of the overlapping Upper series. 



Attention is here invited to the remarkable conglomerate at 

 Coagh, referred to in the recently issued iMemoir.ij; It was 

 formerly (not correctly) described as volcanic conglomerate. 

 "Unfortunately," however, we read "some sections which would 

 have thrown additional light on the matter . . . are no 

 longer visible." If they were, we should probably find that some, 

 if not all, the rock referred to is a true water-formed conglomerate 

 of sedimentary origin. One specimen, which I have seen from 

 the locality, has certainly such an origin. It consists of strongly 

 cemented waterworn debris of basalt evidently formed near the 

 shore line of a sheet of water ; a singularly interesting piece of 

 evidence, marking a break between the basalt from which it was 

 formed and that which covers it. These facts it will be noticed 

 are consistent with the belief that the latter is Upper Basalt § 



The existence of the Upper Basalt, west of the Bann, is 

 accounted for on the presumption that a considerable dislocation 



*Op. tit., pp. 27-28. The lignite is accompanied by "brown haematite." 

 fit is well to note that the deposit of lignite is of such importance, 

 here, as also near Salter's Castle and at Sandy Bay, to he afterwards men- 

 tioned—where the " interbasaltic " position of the lignite might be doubted- 

 that it has been excavated as a fuel ; just as at Black Hill, near Glavryford, 

 and other places where it is of unquestionable "interbasaltic'' origin; while 

 its occurrence at other horizons between basaltic sheets is of comparatively 

 trifling impoi ' 



%Op. tit., p. 10 1. 



§And the occurrence of fragments of rhyolite in the conglomerate is thus 



easily accounted for, the only known rhyolites in the region being interbasaltic. 



