Cole — TJie VarioUte of Cenjg Gwladys, Anglesey. 119 



able distortion and fracture of the more resisting spherulites, while 

 a filmy foliated structure has arisen in the matrix. Along some 

 of these rude planes of foliation epidote has developed in the usual 

 granular condition, and thus appears in the form of strings running 

 parallel to one another across the section. 



A section of the calcareous breccia associated with the variolitic 

 series is also interesting on account of the evidence afforded of 

 the secondary flow of the easily crushed and fissile diabase. The 

 large lumps of pale pink calcite have become broken up at their 

 margins and otherwise influenced by earth-movement ; but at 

 the same time they seem so intimately associated with the diabase 

 as to suggest that they arose in cracks or decomposition-hollows 

 within it, and were brecciated with it at a later date. Grranular 

 quartz, with very irregular boundaries, occurs freely in the calcite, 

 and shows, like the crystals developed in so many altered lime- 

 stones, numerous enclosures of solid matter. Whether this mineral 

 has arisen in situ, how far the calcite patches contain secondary 

 silicates, and the origin of the calcite lumps themselves, must be 

 left for future consideration when a more complete examination 

 has been made of the " limestone " in the field ; but it is very 

 noteworthy that aggregates precisely similar to these larger 

 broken masses are found infilling the vacuoles and cracks in 

 sections of the variolite itself. Uuartz, with the same irregularity 

 of outline and inclusion of the calcite, occurs associated with the 

 calcite granules in these hollows ; hence a breccia very similar to 

 that actually found would result from the crushing of the igneous 

 material which has been so widely permeated and attacked 

 (fig. 5). 



In conclusion, it is remarkable that Prof. Blake should thus 

 have pointed out to us in Anglesey a true variolite within nine 

 miles of the great exposure of glaucophane-schist. Both rocks 

 here form part of the same axis, and have partaken of the same 

 earth- movements ; both are known in their finest and most massive 

 development in a limited district of the Alpine chain. But it is 

 difficult to believe that the association is other than accidental ; 

 and it must be borne in mind that the Anglesey variolite has 

 distinctive features of its own, being the devitrified glass of an 



