576 jNIr. J. Beete Jukes and the Rev. Samuel Haughton on the 



If we examine the map, and observe the nearly straight north-west boundary 

 of the Wexford Cambrian district, A, which, as before said, runs nearly true 

 N. E. and S. W., we should see, at a distance of five or six miles from this boun. 

 dary, and almost exactly parallel to it, a band of trappean rocks. These are the 

 contemporaneous felstones mentioned before, together with a number of intru- 

 sive greenstones and other trap rocks. 



In the intermediate band of country between the Cambrian boundary and 

 these bedded trap rocks, we should find slates dipping in various directions, but 

 generally either N. W. or S. E., and always at angles of 70" or 80°, if not at 90°, 

 or vertical. 



The only nearly continuous section is to be seen along the shore of Wexford, 

 N. and S. of Courtown Harbour; and, judging from that and from other evidence 

 elsewhere, we should say that the greatly contorted and minutely folded and 

 crumpled Cambrian rocks are succeeded on the N. W. by thicker masses of Cam- 

 bro-Silurian black slate, lying in very highly inclined and often vertical positions, 

 and thrown apparently into bolder and larger, though equally abrupt, undulations. 

 If we take the average width of the band thus occupied by the lower beds 

 of the Cambro-Silurian series as five miles, and suppose the total efiect of these 

 undulations to be equal to a double anticlinal folding of their whole mass, we 

 should have one-fifth of the possible thickness as a measure of the actual thick- 

 ness of these beds. This would give about 5000 feet as the probable thickness 

 of the lower part of the Cambro-Silurian beds, those lying between their Cam- 

 brian base and the bedded traps. (See Section, No. 2.) 



The bedded traps occur in two or three or sometimes more hues, very close 

 together, the result either of as many distinct depositions, or of the reappear- 

 ance of one or more bands at the surface consequent on the flexures of the rocks. 

 If we assume one anticlinal fold here, it will give us obviously three lines of out- 

 crop of the same beds, but we shall still be obliged to add two or three thou- 

 sand feet to the 5000 already mentioned for this series of beds ; and all the 

 evidence goes to show that they dip as a whole towards the north-west under 

 yet higher beds. Examining the country immediately to the north-west of this 

 band of bedded traps and their interstratified slates, from the River Barrow be- 

 low New Ross, right through the heart of Wexford to the neighbourhood of 

 Gorey, a high north-westerly dip seems everywhere to prevail over a width of 

 three or four miles, so that we are compelled to conclude that the bedded traps 



