196 Rev. M. H. Close — The Shell-bearing Gravels near Dublin. 



seems uttei-ly impossible that that gravel could have been swept 

 thither by water, along the surface of the ground, for at least those 

 distances, and up-hill too, without having its pebbles nearly all 

 rounded, and without picking up vastly more than one per cent, of 

 granite stones. Again, at Ballyedmonduff pit there is, in one part 

 of the large irregular excavation, and in the upper part of the 

 section, a mass of earthy clay packed with blocks of limestone and 

 grit, some as large as a man's head, and all greatly scratched ; this 

 looks almost exactly like true Boulder-clay (it probably belongs to 

 the Upper Boulder-clay), and it overlies fine gravel and sand (all 

 this is now much obscured by some trees having fallen and torn 

 down the pit escarpment). Any rush of water that could have 

 carried those stones along bodily, without rolling them, could not 

 have deposited the fine materials on which they lie, and must have 

 swept away those fine materials, if they had been already there. 

 Since rushing water is out of the question, as the transporting agent, 

 and also, as will be generally conceded, land-ice, for somewhat 

 similar reasons, we seem compelled to believe, as Mr. Kelly did, that 

 the gravels in question have been transported by floating-ice to their 

 present situations (apparently from a north-westerly direction). 

 The blocks of local granite, weighing sometimes up to 20 tons, 

 which usually lie on the top of the (limestone) gravel, in places to 

 which they could not have fallen or rolled, must have been left 

 there by floating-ice ; but this may have been local and more imme- 

 diately connected with the hills. 



The upper limits of these gravels are clearly not raised beaches. 

 Yet on tlae south-east side of the Three-Eock Mountain, in the 

 Ballyedmonduff bosom, there is an approach to a horizontal upper 

 boundary, at the height of about 1100 feet, extending for about a 

 mile ; and about Caldbeck Castle and the head of Killakee valley, 

 on the other side of the hill mass, a less near approach to such a 

 boundary, at 1200 to 1300 feet, extending for two or three miles. 

 Of course the upper limit of the gravel, as worthy the title of a 

 deposit, does not necessarily indicate the greatest depth of the sub- 

 mergence in the glacial sea. Above that limit many pieces of foreign 

 material can be found, almost to the summit of the Two-Eock 

 Mountain, at the height of about 1760 feet. 



As to the correlation of these high-level gravels with those on the 

 low grounds — it seems impossible, at present, to ascertain their prec^se 

 relations, from direct observation. Speaking roughly, they both 

 evidently belong to the same formation, viz. the Pleistocene " middle 

 sands and gravels," lying below the Upper, and above the true or 

 Lower Boulder-clay. But, considering the most probable mode of 

 transport, and the fact that the submergence of the low grounds must 

 have begun sooner and ended later than that of the high grounds, we 

 may perhaps conclude more definitely that the elevated gravels are 

 contemj)oraneous with some of the middle parts of the low gravels. 



Becapitulation (in different order). — 1. The elevated gravels are 

 Pleistocene, and probably contemporaneous with some of the middle 

 parts of the low-level gravels. 2. They have been carried to their 



