THE VALE OF CLWYD. 17 
FIG. 9. 
Corner of Elwy, above Pontyralligoch, near last letter of Ffynnonfair 
(Scale, 20 feet to 1 inch.) 
a, Red-stained sandstone. ; 
b, Fissile red-stained sandy shale, with plant remains. 
c. Reddish shale. 
ad. Sandstone, 
At the bend of the Elwy, above Glanllyn, near Pontyralltgoch, 
there is a section where the river has undermined the bank and 
caused a slip. Talus generally obscures the upper part of the 
section and covers the base. The sketch (fig. 9) gives the ~ 
result of observations made at various times when different 
parts had been exposed by the rain and river. In the shaly 
beds I found indeterminable fragments of plants. These beds 
are probably about the same horizon as those passed through in 
the shaft close to Pontyralltgoch. 
Now we might speculate upon the correlation of these sand- 
stones and shales which immediately succeed the Mountain 
Limestone of our district. Are they homotaxeous with the 
Millstone Grit or with the Yoredale Rocks, or are they of the 
same age as the upper part of the Mountain Limestone of 
adjoining areas? I confess I have no opinion on the subject, 
and should merely call them Carboniferous sandstones and 
shales, adopting, for the present, local names for the more 
marked sub-divisions. 
Two Well sections in the neighbourhood, which I owe to the 
kindness of my friend Mayor Bircu, are worth recording here, 
though I am unable to correlate all the beds named. 
The first was sunk at Maeselwy, not far from Pontyralltgoch. 
They passed through 
2 iba: he eS rae 54 oO’ 
Clay, with boulders......... 0 10" 
Red laminated marl ........ a 
Red and mottled clay ...... 66' 0 
Red sand passing down into 
sandstone Bre 
The other Well was sunk close to Llanerch, not far from the 
Clwyd. They there passed through 
SPEIRS. Pee ani aia ct em 
Se ARR ok oR Re G10,12' 0) 
Red Sandstone ............ 26 0 
The sandstone at the bottom of the well at Maeselwy was 
probably the stained Carboniferous of the Elwy sections above 
described, but that at the bottom of the Llanerch Well I should 
think may have been New Red, which is exposed in the wood 
~ to the North. 
A boring was made many years ago to ascertain whether the 
coal-measures did not extend beneath the New Red in the 
