324 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



[Mar. 



against the Lower Silurian rocks ; but having seen those near Tagoat 

 to be certainly in the Lower Silurian formation, I doubted the cor- 

 rectness of the supposition adopted at Bunmahon, and a recent 

 reexamination of the county by Mr. Du Noyer has shown these also 

 to be really Lower Silurian red sandstones and conglomerates. (See 

 Explanation of sheets 167 &c., of Irish Maps.) 



2. Hooh Head. — The Upper Palaeozoic rocks which strike into the 

 sea south of Duncormick reappear on the coast, in the promontory 

 of Hook Head, partly in consequence of a change in the strike of the 

 beds, which there dip nearly due south, and partly from the land pro- 

 jecting farther to the south, as we proceed westwards. Fig. 2 wiU 

 give an idea of the lie and position of the Carboniferous Limestone 

 and undoubted Old Eed Sandstone here ; the latter reposing on 

 slates and grits which belong to the Lower Silurian grou]3, as is 

 evidenced by their fossil contents at Duncannon Eort and else- 

 where*. These Lower Silurian beds are greatly contorted, as is 

 shown in the cliffs of Waterford. Harbour for several miles. 



The Old Eed Sandstone rests on the edges of these contorted beds 

 quite unconformably, as is shown in section fig. 2, and dips from 



Pig. 2. — Section of part of HooTc Head. 



, ^ , .„ T , { d^. Grey often flasrffy limestone. 



d. Carboniferous hmestone. ^ ^i_ Black shale highly fossiliferous. 



c. Old Red Sandstone. 

 b. Lower Silurian. 



f Eed and yellow sandstones and shales above. 

 \ Eed sandstones and conglomerates below, 

 f Indurated shales, slates, and fine-grained grey 

 1 grits. 



them to the south, as a whole, but is itself undulated at slight angles 

 and broken by faults probably of small throws. It is well shown in 

 cliffs about 40 feet high for about a mile and a quarter along the 

 shore of Waterford Harbour and for nearly two miles along the 

 eastern shore of the promontory, which does not cut so directly across 

 the strike of the beds as the western shore does. 



The thickness of the Old Eed Sandstone here is not exactly 

 determinable, owing to its disturbed " Ke," but it must be at least 

 six or seven hundred feet. The lower beds consist of red sandstones 

 and red shales, with beds of red conglomerate occasionally. Higher 

 up the conglomerates become more massive, and beds of white con- 

 glomerate occasionally appear among the red. About the middle of 



* See the list of Fossils and the Palseontological Notes by Mr. W. H. Baily 

 in tlie " Explanation of sJieets 169 &c. of the Irish Maps in the Memoirs of the 

 Geological Survey." 



