18 NOTES ON THE GEOLOGY OF 
Northern part of the Vale, and it is recorded that the attempt 
was not abandoned until they had passed through 98 feet of 
sand, gravel, and clay, probably recent estuarine deposits, and 
648 feet of alternations of red and white sandstones and shales. 
‘A subsequent boring (1875-6) near Aberkinsy was given up 
after they had passed through 480 feet of red rock. At 300 feet 
they came upon bands of red marly shale. Much of the 
material which was brought up was a dark red soft clayey 
sandstone; but it was so crushed and mixed by the boring 
apparatus that it was difficult to form an opinion as to its 
character. I have been unable to learn, in either case, whether 
some of this red rock was not stained Carboniferous, nor do I 
know whether those who put down the bore consulted anyone 
competent to give an opinion on the question. The faults of 
the district should be carefully worked out before anyone can 
safely speculate upon the difficult question of the occurrence 
of coal under the New Red, and as I am aware that my friends 
Mr. TipDEMAN and Mr. STRAHAN are engaged upon this work, 
I will not offer any remarks about it further than to point out 
that there is evidence about W. of Ruthin, Llanrhaiadr, 
Pontyralltgoch, and Cefn, of systems of faults, affecting the 
Silurian and Carboniferous, running into the valley oblique to 
its general direction. 
There seems to be reason for suspecting a fault running N.E. 
and S.W., about 50 yards lower down the road than the Pont- 
newydd Cave ; from the abrupt ending of the limestone in a 
.sort of cliff on that side ; from the occurrence of fragments 
of vein stuff, calcite, hematite, &c., along that line; and from 
the depression crossing the hill in its continuation just opposite 
the school. 
Here it is probably cut off by another fault running N., 10° 
W., from near Dolben, through the hollow, W. of the school, 
and through the yard of Bedd-y-cawr. 
N. of the “en.” in Pen-y-cefn, W. of St. Asaph, there are 
some lodes which have yielded a small quantity of lead. They 
run magnetic N. and S., and magnetic E. and W., and also 
sometimes along the bedding, dipping about 10° E.N.E. to 
N.N.E. All these lodes are very irregular, and can hardly be 
said to be more than pockets and veins of various minerals in a 
crushed and broken part of the limestone, but that crushing is 
connected with a magnetic N. and S., and a magnetic E. and W. 
set of faults. There are many voogs or caves, some of which 
are water channels, some filled with clay, and some generally 
dry, except after wet weather. The water is checked by the 
rapid accumulation of stalactite. The clay did not look as if it 
had been carried in through large openings, but as if it had been 
filtered through rubble or small fissures. 
When the lode conforms to the bedding there is generally 
below it a bed of soapy shale, which seems to have arrested 
