Vol. 51.] THE COUNTRY AROUND FISHGUARD. 151 



assigning of the scattered outcrops to their proper horizons a 

 matter of difficulty and uncertainty. The exposures at Trefelgarn 

 and Cam Llys are examples. Small local disconnected flows issuing 

 from different vents on approximately the same horizon seem a 

 reasonable explanation of this variation. 



Above and in close connexion with the Castle Point lava-flows 

 are certain greenish-grey fossiliferous ashes, exposed within the old 

 fort on this Point and on the slopes outside of it. On the Geological 

 Survey map only greenstone is there indicated. These ashy beds 

 strike across the mouth of the harbour and occur on Saddle Point. 



The Carn Ffoi mass of volcanic rocks is found to be not an 

 isolated block, but a portion of the same broad belt that is conspi- 

 cuous near Bwlch Mawr ; this belt has been traced eastward, south 

 of Newport town, to the banks of the river Clydach. 



The separation of the closely intruded sheets of diabase in the 

 Llanllawer and Carn Ingle district must be to a large extent 

 arbitrary, in the absence of definite field-evidence. I do not see 

 sufficient cause to justify mapping them in so many narrow parallel 

 6heets as are indicated on the Survey map ; at any rate the ground 

 is now completely overgrown, and the solid rock is rarely exposed 

 at the surface. 



III. Folds, Faults, etc 



On Pen Caer the strike of the beds is generally E.N.E. and 

 W.S.W., but east of Fishguard, and near Newport, it changes 

 gradually to nearly due east and west. The disturbance in the 

 strike on Pen Caer seems, to some extent, due to the intrusion of 

 the huge mass of diabase. 



The dip of the beds is to the north or N.N.W. at high angles 

 (60° to 80°). Comparatively little folding on a large scale appears to 

 have taken place ; but round the cliffs of Fishguard Harbour and on 

 the steep bank by the road connecting Upper and Lower Fishguard 

 the slates have been thrown into numerous small folds, and exhibit 

 small normal and reversed faults. 



The contorted strata in the cliffs of Din as Head have been figured 

 in the Geological Survey memoir, and the plications in similar beds 

 are noticeable near Newport. Instances of local flexures are fre- 

 quent in the cliffs where the latter are composed of slates, and many 

 are marked on the Geological Survey map. 



The faults in this area are not numerous. The most impoi-tant 

 one runs from Pwll Ceunant, which is on the coast between Fish- 

 guard and Dinas Head, in a south-easterly direction past Cilshafe 

 and Llanllawer. By means of it the Upper Llandeilo Beds between 

 Pwll Ceunant and Newport are shifted back southwards, the down- 

 throw being to the east. 



Another fault farther east, with a downthrow on the same side, 

 starts from Cwm Bhigian, and runs with a southerly course towards 

 the farm named ' Parke ' on the 6-inch map. This also gives the 

 beds to the east of it a further shift southwards. Both these faults 



