IxXXvi PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1 898, 



pletely filled up, and some large bones touclied the roofs, 

 while others were forced into small fissures. 

 5. When subsequently the ice from the western (Arenig and 

 Snowdonian) and from northern areas reached this district, the 

 cavern was again partially disturbed, and some of the mixed 

 drift from those areas was introduced into it. The cavern was 

 afterwards completely covered over by the mixed drift, and its 

 exposure subsequently has been due to subaerial action in 

 post-Glacial times, and in part to mining operations. 



Cae Gwyn Cave. 



When referring, in my paper before the Geologists' Association in 

 1885,' to this cavern, I stated that when I first crept into it I 

 recognized that it was an entirely unexplored and undisturbed 

 cave, and that we had at that date penetrated to a distance of 150 

 feet, but that further progress had been impossible, because there 

 was only a very small space between the roof and the material 

 filling the cavern. I then state : — ' The original entrance would be 

 probably from 20 to 25 feet nearer the valley, as there are evidences 

 that the limestone here has been, at some previous time, quarried 

 and removed. Between the entrance and the chamber worked there 

 is an average space of from 2| to 4 feet between the surface of the 

 material on the floor and the roof, but beyond this it gradually 

 diminishes. There was scarcely any drip in the cavern, and the 

 earth is, in places, quite dry. A red earth covered the whole floor, 

 and this was much burrowed by rabbits. In this earth a few recent 

 bones were found, but no remains of extinct mammalia. After 

 removing this earth in the chamber we came upon a tolerably hard 

 floor, which, when broken through, was seen to consist of several 

 layers of ferruginous clay and calcareous matter. Under this floor 

 was found what might be called here the cave-earth, being apparently 

 the usual material found at this horizon in the caves of this 

 district, and that in which the remains are usually enclosed. 

 This earthy clay is identical in appearance with the Upper Boulder 

 Clay in this area, especially that about St. Asaph and in the centre 

 of the Yale of Clwyd, and contains rolled pebbles of felsite, quartz, 

 quartzite, sandstone, Silurian and older rocks, as in that deposit. 

 There were also fragments of an old stalagmite-floor. The bones 



^ • On some Eecent Eesearches in Bone-Cayes in Wale?,' Proc. Geol. 

 Assoc. Tol. ix (1885) p. 1. 



