572 Mr. J. Beete Jukes and the Rev. Samuel Hatjghton on the 



or two coats of greater or less thickness may have been removed from the 

 hills; the present valleys may have been excavated from between those hills; the 

 ravines and water-courses that traverse their sides may have been graven on 

 them ; the present plains may have had their surfaces ground down to a little 

 greater depth — in fact, a skin of a few scores, or in some places a few hundreds, 

 of feet in thickness, may have been subsequently removed from the country. 

 Nevertheless, the main fact remains, that the principal part both of the denuda- 

 tion and of the elevation and inclined position of the rocks of our district, had 

 been produced previously to the deposition of the Carboniferous rocks, inas- 

 much as the latter repose at low angles, and in comparatively undisturbed posi- 

 tions, on the uplifted and eroded edges of the former. 



It would seem probable also, from the absence of all formations of an age 

 intermediate between the Carboniferous and the Pleistocene, that our district 

 remained tranquilly above water during all the secondary and early tertiary pe- 

 riods, and was only once more bodily depressed below the sea at some late ter- 

 tiary period. 



IV. Position and Lie of the Rocks. 



Although the denudation of the country had been nearly or entirely com- 

 pleted at so early a date, nothing is more remarkable in our district than the 

 extent to which it has proceeded. Notwithstanding the very highly inclined 

 position of the beds, and their numerous and large flexures and contortions, 

 and notwithstanding the hardness and toughness of the materials of which they 

 are chiefly composed, so greatly have they been denuded and worn down in 

 order to produce the present surface of the ground, that they rarely form any 

 continuous ranges of hills, or any other prominent external features, which 

 assist us in drawing conclusions as to the position of the beds below the sur- 

 face. Almost the whole of the county of Wexford is low, gently undulating 

 ground, thickly and widely overspread with " drift;" and although Wicklow is 

 more hilly, yet the hills composed of stratified rock are generally rounded and 

 isolated mounds, separated by wide valleys, and low grounds, in which " drift" 

 and superficial matters are largely accumulated. Good continuous sections, 

 therefore, across the strike of the beds, or continuous exposures of rock ranging 

 along the strike, are almost entirely wanting, and we have chiefly to trust to the 

 collocation of many single detached observations for arriving at any knowledge as 

 to the thickness of the formations, or the composition of their several portions. 



