Quart. Journ. Geol. Soc. Vol. LXIX PL XLVIII. 



-//.,,■/:..„/,(/ .v,, ■/;,,„ (( /,.,i :/ tli, Afon lac 



—f 



& ! I'll 



lie BdlBc; Bl j; B(h UJ3 " "~"B< 



tti = i\ni,t-v.«.ill..ii Sli.iles. 



Mid, = Uppm Gr»n i 

 1>.I - J)..!-:,u I Ii.l -^ Mi. 101. l'ui|.l.. S11L.--1 ,,. Bn = Br; 



', Scale of Miles 



Afon Twymyn 

 Dolgadfan 



„r,:,j „ ,, /, /-,./„,(/;,„ /.. ZW, r&% wrwi ffl wj<M *W*%. "" "•< »«'' '"' '' ''" " '" " ; '' ■ 



Carnedd Newydd Fynyddog Afon Cwm Calch. Talerddig 



^ n ^ '".^t-ysgollon Shales Ca 



'■:-; 



B, 



Ac Ab Ba Ba/ ^"r y '1 , 



\'* G rou 



Croup Ba 4 



