QUATERNARY DEPOSITS OF BRITISH ISLES BROOKS. 329 



5. Lower, stiff marly bowlder clay with shells. 



4. Lower " head." 



3. Blown sands. 



2. Raised beach gravels, with erratics from the east. 



1. Beach platform. 



Unfortunately no fossils have been found in the beach or the blown 

 sands, but, by analogy with Gower and Selsey, there is little doubt 

 that a warm period intervened between the floating-ice period of the 

 raised beach and the glacial period of the lower bowlder clay. The 

 latter must accordingly correspond to the bowlder clay of south 

 Wales, and to the second glaciation of England. This interpreta- 

 tion is supported by the general gray color and nondecalcified state 

 of the shelly lower bowlder clay, which is in direct opposition to the 

 usual characters of the clays of the first glaciation in Europe. 



The question then arises, Are there any deposits in Ireland, apart 

 from the raised beach with its ice-borne erratics, which can be cor- 

 related with the first glaciation of England ? Owing to the intensity 

 of the last general glaciation and the small amount of work done on 

 the Irish Quaternary we can not expect much, and we get very little 

 evidence of such deposits. In Newtown colliery (sheet 137) a bed of 

 highly bituminous peat was found between two beds of bowlder 

 clay, but no further particulars are given. The fact that the peat is 

 described as "highly bituminous" supports its interglacial age. In 

 the neighborhood of Armagh stumps and branches of black oak like 

 that from bogs are stated to have been found in bowlder clay at 

 several places (sheet 47). 



Remains of a bowlder clay belonging to an earlier glaciation have 

 possibly been found near Dublin (104). Here we have the usual 

 gravelly upper bowlder clay with rounded stones, mainly limestone, 

 resting on the truncated edges of a series of sand and gravel beds 

 interdigitating with red clay which evidently represents the lower 

 bowlder clay. (The red color of this clay is stated by G. A. J. Cole 

 and T. Hallissy (105) to be due to marine action.) The authors of 

 the Dublin memoir state: 



A remarkable feature of the red bowlder clay 300 yards south of the point 

 at which the Loughlinstown stream enters the sea is that it contains large 

 irregular masses of purple clay with sharply defined outlines, which appear 

 to be true bowlders, in some cases sharply fractured, the gaping cracks being 

 filled with sand, gravel, and clay from the surrounding matrix. 



These bowlders are nearly identical with 35 feet of laminated purple 

 bowlder clay seen at Kill o' the Grange, which is thus evidently older 

 than the red clay in Killiney, but it does not appear how much older, 

 unless we can read the earlier work of A. Bell into the section here. 



Mr. A. Bell (1885-1891) investigated on behalf of a British Asso- 

 ciation committee the Manure gravels of Wexford and other post- 



