Y Foel Fras, Caernarvonshire. 139 



Evidence for the Aber-LIanbedr fault has been found near the 

 source of a small tributary which enters the right bank of the 

 Afon Anafon 500 yards below the lake, where rhyolites are found 

 faulted against contorted slates. Fault breccias provide further 

 evidence 500 yards lower down the Anafon, and also near the north- 

 eastern extremity of the granophyre laccolith in the groove cut 

 by a small stream which enters the left bank of the Anafon after 

 draining the north slopes of Llwydmor Bach. 



The area to the north-east and north-west of Llyn Anafon is 

 much disturbed by faulting and needs further investigation. The 

 work is being continued, and it is hoped that a map of the area on 

 the 6 inch scale will be published at a later date together with a more 

 detailed account. 



