﻿552 



DE. T. GEOOM AND ME. P. LAKE OX THE [ISToV. I908, 



slate. Some of the sandstones 

 they are coarse and contain 



rS 



. OS "» 











n ?, 



V4 



«2 ^ .*;■ c 

 . -• M OQ -= >;^ . 



^g M oS 

 II II II II II II 



II IM 



are very compact, but more generally 

 a large amount of volcanic material 

 and many fragments of slate. They 

 are finely exposed in the quarries 

 that have recently been opened on 

 the right bank of the Ceiriog im- 

 mediately above Pandy, and may 

 also be seen in the old Teirw-Hill 

 quarry, in the corner between the 

 Teirw and the Ceiriog. 



The sandstone is followed by 



some 500 or 600 feet of slaty 



fcp beds with occasional siliceous bands. 



•§ They appear at intervals in the 



wood on the right bank of the 



. Ceiriog, and also on the lower 



^ slopes of Craig-y-Pandy. 



Craig-y-Pandy Ash. — Upon 

 these slaty beds rests the second 

 ash of the Geological Survey. It 

 forms the fine crag known as 

 Craig-y-Pandy, and has been 

 quarried from time to time both 

 on Craig-y-Pandy itself and also in 

 the ' China-clay Quarry ' ^ on the 

 right bank of the river. The rela- 

 tions of this band to the beds above 

 and below are sometimes very com- 

 plex, but, as we shall show sub- 

 sequently, the greater part, if not 

 the whole, consists of tuffs and 

 ashes, as the officers of the Geolo- 

 gical Survey and most other ob- 

 servers have supposed. 



CO ^ OD 





II II II II 11.11 



intervals for a considerable 



Bryn Beds. — Immediately over- 

 lying the Craig-y-Pandy Ash is a 

 series of slates and sandstones, the 

 base of which is seen at the northern 

 edge of the China-clay Quarry. 

 About 60 or 70 feet above the ash 

 is a sheet of intrusive rock which 

 is extensively worked in Coed-y- 

 glyn Quarry. The sheet appears 

 to be very irregular and discon- 

 tinuous, but may be traced at 

 distance. It has apparently been 



Paudy Quarry ' of the 6-inch Ordnance-Survey map. 



