Lower Palceo zoic Rocks of the South-East of Ireland. 573 



The granite hills, indeed, seem at first view to be an exception to the above 

 statement, since they form a continuous range of lofty land over a part at least 

 of the district; but even this rock has been so largely denuded as to form a •wide- 

 spread expanse of low ground in the county of Carlow; and the broad valley 

 of the Slaney cuts right across it, separating the granite hills of the Dublin and 

 Wicklow Mountains from those of Mounts Leinster and Blackstairs on the bor- 

 ders of Wexford and Carlow. 



In examining the position and lie of the rocks, therefore, our conclusions 

 will principally be drawn from observing the boundaries of the several forma- 

 tions, and the directions of their subordinate groups of rock, as laid down on the 

 maps, or from the collection and comparison of separate data, rather than from 

 direct observations in the field. 



The district divides itself naturally into seven areas that admit of separate 

 description: three composed of Cambrian rocks; two of Cambro- Silurian; one 

 of Granite ; and one partly of Granite, and partly of Cambro-Silurian 

 rocks. 



The Cambrian areas are: — A, that of "Wexford; B, that of N. Wicklow; 

 and C, that of Howth. 



The Cambro-Silurian areas are : — D, that of Wicklow, Wexford, and Water- 

 ford; E, that of Kildare, Wicklow, and Dublin. 



The Granitearea isF, that which stretches from Dublin Bay to near New Ross. 



The remaining area, G, is that south of Wexford Harbour, which we may 

 call the Carnsore area. 



A. — The Wexford Cambrian district stretches from the east point of Bannow 

 Bay to Roney Point, three miles south of Courtowu Harbour, its total length 

 being thirty-six miles. It forms the Forth Mountain district near the town of 

 Wexford, where it has a surface width of about seven miles, and attains, as its 

 highest elevation, an altitude of about 700 (697) feet above the sea. Except 

 on the Forth Mountain tract, it forms generally a low, gently undulating country, 

 entirely covered by thick masses of sand, gravel, and marl, the Cambrian beds 

 being only seen in detached quarries, or in low cliffs on the sea-shore, or on the 

 banks of the Slaney for a few miles above Wexford. 



Where seen, these beds are always found to be greatly contorted; the most 

 frequent strike, however, being nearly N. E. and S. W. The north-western 



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