jff. F. Hall — Glacial Deposits of Llandudno. 509 



Analyses of the lignite of Talcahuano, by Admiralty Investigation 

 Committee : 



Ash 6-92 



Carbon 7071 



Oxygen, Sulphur, Nitrogen 15'93 



100-00 



Of Lota coal, by Dr 

 Ash ... 

 Carbon 

 Hydrogen 

 Oxygen 

 Sulphur 

 Nitrogen 



Playfair : 



5-68 



78-30 



5-30 



8-37 



. 1-06 



. 1-09 





10000 



Of Lota first seam, by Mr. Abel, of Coquimbo : 



Ash 



Carbon 



Hydrogen 



Oxygen and Nitrogen 



. 2-05 



. 83-70 



1-02 



. 13-23 







100-00 



IV. — On the Glacial and Post-Glaoial Deposits in the 



Neighbourhood of Llandudno. i 



By Hugh F. Hall, F.G.S. 



I HAVE been led to think that a description of the drift-beds in 

 the neighbourhood of Llandudno might be interesting to the 

 Section, on account of the discussion which took place on Mr. 

 Morton's paper, as to the description of pebbles contained in the 

 " Boulder-clay." 



The section I have drawn is a general section, taken from a care- 

 ful examination of the beds exposed at the following places : Go- 

 garth, West side of the Little Orme, East side Little Orme, Dy- 

 ganwy, Ehos, Colwyn, and Llandulas. 



The base-bed taken is the Mountain Limestone. At the Little 

 Orme is exposed above this a bed of three to five feet in thickness of 

 Mountain-limestone rubble, angular fragments, which may probably 

 be accounted for by the action of frost during the earlier part of the 

 Glacial period, breaking up the exposed rock into fragments, which 

 in this sheltered corner have not been carried away by the ice-sheet 

 which has produced the overlying Boulder-clay, and in its greatest 

 exposure is about 150 feet in thickness. This bed I regard as the 

 result of the grinding down of the subjacent strata by land-ice, 

 which, at this period, must have covered the land down probably to 

 the water's edge ; in fact, the true Glacial period. The materials of 

 which these beds are composed are invariably those which would 

 result from the breaking up and grinding down of the rocks 

 in the immediate neighbourhood. Thus, at Ehos, it is a very 



^ Read before Geological Section, British Association, Liverpool, 1870. 



TOIi. VII. — NO. LXXTII. 33 



