﻿188 TEEMADOC SLATES OF SOUTH-EAST CAENAEVONSHIEE. [May I9IO, 



converted a thick belt of rock on either side into the condition of 

 a quartz-chlorite-schist. That fault was a normal fault of slight 

 throw. 



Further, he could offer no opinion as to the exact relative ages of 

 the Angelina Eeds and the beds with Peltura punctata in South 

 Wales. He had collected several examples of a Peltura not unlike 

 Peltura punctata from the Penmorfa Beds, and could see no inherent 

 reason for excluding the Peltu?'a-punctata Beds from the Tremadoc 

 Series. 



He believed that the unconformity between the Garth Hill Beds 

 and the basal Ordovician grit was due to the same north-and-south 

 folding as that which had corrugated the Cambrian rocks of the 

 Harlech country ; and as, at Llanystumdwy (1 mile west of 

 Criccieth), there was complete passage from the uppermost Ordovi- 

 cian into the Skelgill facies of the Lower Llandovery, he could not 

 agree that the stratigraphical break between the Cambrian and the 

 Ordovician Systems in this area was of less importance than the 

 unconformity between the Ordovician and the Silurian. 



