296 



M 



e ^ 



Hi <» 



E. Hull— General Relations of the Drift Deposits. 



Dr. Scouler,' and subsequently by Dr. Oldham. 



At Kingstown, the Upper Boulder-clay may 



be observed to rest on the middle gravel ; and 



at various points between Kingstown and 



Dalkey, the Upper (or Lower) Boulder-clay is 



^ found to rest on a surface of granite remark- 



I ably moutonneed and striated. The general 



« direction of the ice-flow being from the N.W. 



I or N.N.W., a direction pointing to the central 



rt plain of Ireland.^ 



*' Proceeding further South, and rounding the 



granite and schistose cliffs of Killiney Hill 



and Mount Malpas, the shore sweeps inland, 



with a gentle curve terminated to the South 



^ by the bold cliffs of Bray Head. It is along 



•I this shore that the cliffs of Drift are exposed 



I to view, which are represented in the accom- 



g panying illustrations (Fig. 1). The whole 



^ section forms a basin or trough, the beds 



I rising both to the North and South. At the 



^ extreme Southern end of the section, we find 



the three divisions of the Drift in the same part 



of the cliff, which is about 35 feet high, the 



Lower Boulder-clay only just showing itself at 



> the base. The middle sand and gravel (Fig. 2) 



^ is obliquely laminated, very coarse, and contains 



I fragments of shells. The Upper Boulder-clay 



(Fig. 3) is composed of stiff reddish clay, with 



1 large boulders of granite, Silurian grit, etc., 

 -g and glaciated stones. It descends from the 

 ^ top of the cliff to the base, with a gradual slope, 

 I cutting out beds of gravel in the middle divi- 

 g sion, as shown in Fig. 2. This circumstance is 

 ci exactly similar to one which Inoticed in Lanca- 

 shire, where I often found the Upper Boulder- 

 clay resting upon a greatly eroded surface of 

 the middle sands, and of which illustra- 

 tions will be found in my paper on the Drift de- 



>> posits near Manchester.^ 



I Eeturning to our section, we find the Upper 



^ 2 Boulder-clay forming the cliff for some dis- 



I tance : but on approaching the outfall of Lough- 



I linstown Brook, it gradually descends under a 



3 ^ Journ. Geol. Soc. Dublin, vol. i., p. 270. 



^ " Some of these cases of strics were originally noted 



by the late Mr. Du Noyer. See Explanation of sheets 



102 and 112 of the Geological Survey of Ireland. It 



is remarkable that the striae along the coast near Dublin 



point in a direction, and have been produced by ice comino- 



from a region for the most part devoid of elevation. 



3 Mem. Lit. and Phil. Soc. Manchester, vol. ii., third 

 series, p. 453. 



