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PROF. T. M'KENNT HUGHES ON THE 



On the other or eastern side of the Yale of Clwyd, the Talargoch 

 beds abut against the rock at the northern end. Here mining 

 operations have been carried on along the rock-surface, seeking for 

 the lumps of ore that occur in the base of the gravels like the 

 " stream tin " in Cornwall. I have found shells, Tellina balthica, 

 in some more clayey beds along the edge of the rock, and, in the 

 deep gravel at the bottom of the workings, bones &c. are said to 

 have been found (Proc. Chester Soc. Nat. Sci. 1884, p. 31) in old 

 times, and in more recent times similar discoveries have been re- 

 ported. 



If we are ever able to distinguish between the deposits of the sub- 

 mergence and those of the emergence, the Talargoch gravels will, I 

 suspect, be referred to a late time in the age when the land was 

 coming up again. 



Now we must bear in mind, First, that the colouring-matter 

 of the New Red Sandstone occurs as a thin pellicle of oxide round 

 the grains, so that when they have been much knocked about, the 

 sand is colourless, and the oxide is carried in the water to stain new 

 beds of finer texture where it can settle down. 



Secondly, that the New Red does not attain any considerable 

 elevation in the Yale, so that in the submergence it was soon below 

 the reach of ordinary denudation. Thus we may expect that many 

 of the drifts derived from it will not be red, because the colour has 

 been washed out, and many drifts of the same, or only slightly dif- 

 ferent age, will be the one red, the other grey, according as any 

 source of the red colour was still in the line of drifting or not. 



Great masses of grey gravel, near Brynypin, at an elevation of 

 about 500 feet, clearly belong to some part of this age • and when 

 the sea was there it must have left gravel and sand above the more 

 ancient drifts along the Elwy above Pontyrddol. 



At Brynypin there must have been a tidal swill. All down the 

 east slope of the same hill, on the south side of Bodelwyddan Park, 

 the red-clay drift is seen in the road- cuttings, where boulders of 

 north-country granite are not uncommon, at any rate up to a height 

 of 300 feet. 



On the eastern flanks of the Clwydian range there are grey gravels 

 high up the hill on the south side of Cwm Nannerch, for instance, 

 which might well belong to this same age ; but in the absence of 

 fossils and opportunities for a more careful examination of the 

 constituents, we must suspend our judgment here ; for they 

 might be also the gravels at the foot of the great ice, when it had 

 receded just so far. The esgair drift below also, near Bryn 

 Nannerch, requires more evidence before we can feel sure about 

 its age. 



Three miles and a half to the E.S.E. from here, on the hill-top 

 near where the " g " of Caerhug is engraved on the 1-inch map, 3| 

 miles W.S.W. of Northop, some 650 feet above the sea, I have 

 collected sea-shells in the drift. This is an interesting place to find 

 them, for it lies halfway between the shell-bearing beds of Moe 

 Tryfan and the similar deposits near Macclesfield ; while if we trave 



