534 H. HICKS ON THE PRE-CAMBRIAN 
under the latter*. This is clearly due to the influence of a split 
fault, as shown in the plan. Behind the kilns on the opposite 
side of the river is the section mentioned by Dr. Geikie, where, 
according to his view, as stated in his paper (p. 276), ‘‘ another 
junction of the granite with the Cambrian beds can be seen. The 
Fig. 7.—Skeich of Quarry in the Allan Valley on north side of 
Porth-clais, showing faulted contact of Cambrian Rocks with 
Dimetian. 
i] 
vis > : 
= Va Wess 
= Ygn_ Oye anes) 
RYAN 
4 7 <A ARs DAA 
fra NOS 
Ti 
————__—__ c SLES a 
Se Se LIEGE ne rm — 
Zs) 
3. Red shales (Lingulella primeva). : A. Dimetian. 
2. Greenish sandstones. Tea. F. Fault. 
Fig. 8.—Quarry on roadside between Porth-clais and Rhoseribed, 
showing faulted contact of Cambrian with Dimetian. 
. 
oe ES “a 
7a Rae Se 
Yip tn -* 
MUN 
sl Mii 
= RNIN Ln OES tee PZ 
LL LARS | eee 
See oy 
1. Cambrian basal conglomerate. A. Dimetian. F. Fault. 
latter consist of greenish shales and sandstones dipping N. 20 
W. at 55°, and are here again distinctly overlain by the granite, 
which cuts across the edges of the strata that dip beneath it.”. 
The interpretation of this apparent dipping under is the same as 
on the opposite side, and it is due entirely to the same fault. 
* The place which Dr. Geikie exposed when at St. David’s, as mentioned 
in his paper, is the flat surface marked with 1 near the centre of the sketch. 
Tt was further and more freely exposed during my visit with Prof. Hughes 
and party. 
