Mr Stanley's Memoir on a Cave at Cefn m DenUgshire. 51 



mentioned, existing on the southern side of the main opening 

 vault, till it spouted forth at the aperture on the south-eastern 

 side of the cliff, which may account for the trifling appearance 

 of loamy deposition in these passages. I am aware, however, 

 that, on high authority, to which I feel inclined to pay the great- 

 est deference, it has been urged that this loamy stratum is to be 

 attributed not to inundation, but to filtration of earthy calcare- 

 ous matter through the rocky roof. In answer to this, I would 

 merely remark, that the solid mass of superincumbent rock from 

 40 to 50 feet in thickness strongly militates against this view, 

 and further, that it receives little support on inspection. For 

 on examination it will be seen, that the upper surface of the de- 

 posit has every appearance of having originally formed a com- 

 pact mass, completely filling up every cranny and fissure to the 

 very roof, though at present there is a void space, varying from 

 8 inches to a foot between the surface of the diluvium and the 

 roof. Now, if the sediment had entered by filtration, this sur- 

 face must have followed the laws of gravity, and formed a line 

 parallel to the present horizontal strata observable in the mass 

 of the deposit ; but instead of so doing, it follows the irregular 

 sloping of the roof, which dips to the north at a small angle, as 

 if the upper portion of the mud had gradually and uniformly 

 collapsed into its present inclined position, just as the muddy 

 deposit near Laureana, quoted by Mr Lyell, vol. i. p. 427, is 

 said to have collapsed to the extent of 10 palms. It would be 

 presumptuous to express any positive opinion as to the probable 

 origin of these caverns, so frequent in the limestone ranges, in 

 the face of the many ingenious conjectures of more experienced 

 geologists. It is, however, worthy of remark, and will be easily 

 seen on reference to the sketches, that although the general cha- 

 racter of the whole upper line of stratification in the cliffs from 

 its southern extremity at Cefn to its northward termination, are 

 horizontal, yet, at the level of this cave, and near its aperture, the 

 beds of limestone have a visible curve upwards, as if some sort 

 of pressure had dislocated or bent the weaker joints of the cliff, 

 and thereby enlarged, if not actually caused, the cave under 

 consideration. 



For the information of those who may be induced to visit this 

 spot, as attractive to the artist from its picturesque beauty, as 



d2 



