



- 



BREIDDEN HILLS, MONTGOMERYSHIRE. — VOLCANIC ASHES. 187 



few miles south of Bala lake. The meaning of this circum- 



Uppee 



Gallery. 



\ 



k stance is, that in the middle of the period when the Bala 



beds were formed, the area of what is now Caernarvonshire Wall " case4 

 was the centre of a district in a state of volcanic activity, 





which did not extend far to the south. 

 39a and 39b. — The same, fused in a common air fur- 



j 



nace. 

 40. 



Concretionary felspatiiic ash. 



Pen-y-rliiw, 





%: 



lit: 



-: Ik • 



three quarters of a mile north-west of Bala, Merionethshire. 

 Map 74, N.W. Felspathic layers, much decomposed and 

 containing ochrey particles, alternating with felspathic con- 

 cretions. 



41.— Brecciated volcanic conglomerate and grit. 

 three quarters of a mile W. by S. of Pwlheli, Caernar- 



vonshire. Map 



Alternations of fine and coarse 





volcanic breccia and grit. Greenish, with pebbles of greenish 



and black chert or jasper. 



i 





Mi 





- 





Ashy Series of the Lland: 



Montgomeryshire. Map 

 abo ye. 



Hills, 



No. 3 





'./ 



42— Compact felspathic porphyritic ash. — Breidden 



t 



y 



Mont 



Map 60, N.E. 



Dark and greenish- 



:: 







n ' 



^ 



grey granular felspathic rock, with small brilliant felspar 

 crystals interspersed. 



These bedded igneous rocks lie in the Llandeilo flag 

 series, and are probably the general equivalents of some of 

 the higher igneous rocks that lie in the Llandeilo rocks 

 between the Stiper stones and Chirbury, from four to six 



Montgo 



43— Felspathic ash— Moel 



Montgomery si 



Map 



Breidden Hill, 



N.E. White compact fels- 



/ 







pathic rock, with green chloritic particles interspersed; 

 weathers to white earth (Kaolin) ; gives out a strong 

 laceous odour. From the same set of rocks as No. 42. 



