KiNAHAX — On Gra)dfic and oiher Ligenite EocliS. 113 



blocks of felstone were obsei-red in a conglomeritic schist ; these were 

 not only remarkable but highly instractive, for they not only proved 

 that f elstones must hare exi&led prior to the formation of this sedimen- 

 tary rock, bnt also that some felstones are less susceptible of change than 

 whinstones, for while the matrix was a well marked schist, and in the 

 associated blocks, mostly homblende-rock, there was more or less folia- 

 tion, these were veiy similar to ordinary felstone, the only alteration 

 that was evident being an almost microscopic foliation, obscurely 

 visible to the naked eye, on weathered surfaces. 



The foliation in the conglomeritic-scliists is irregular. That in the 

 enclosed blocks may lam in various dii-ections, while that of the matrix 

 has a gi'eater or less tendency to curl round the blocks, but in some 

 cases it is veiy irregular (fig. F, PL 9). 



The fine hornblendyte is often more or less associated with 

 homblende-roek. Sometimes the latter rock at the margin gTaduates 

 into it, when it is impossible, except pieces of the rocks have been 

 subjected to microscopic examination, to say where one rock ends and 

 the other begins ; while at other times it occru's as lenticular patches 

 or layers enclosed in the mass, or as thin partings. In such cases it is 

 probable they were formed fi'om the disintegrated poriions of the ori- 

 ginal igneous rock due to its contact with water, the enclosed layers 

 and patches marking the limits of different flows or beds. "^^ Fine horn- 

 blendyte may also occur as independent beds when it often gra- 

 duates into chlorityte, talcyte, steatityte, or homblendic-micasyte, 

 but it is most remarkable when it appears associated with quartzyte, 

 for, as previously remarked, in such places it rarely gxaduates into 

 that schist, such masses apparently being due to showers of tuff 

 falling on water and settling down ia one place, forming a distinct, 

 small, but independent, patch of rock. All the fine homblendytes are 

 more or less epiclotic or they may change into a rock that might be 

 called epidoticyte. 



The weathering of these fine schists and also many other varieties 

 of schist that are more or less basic should be noted, for in them the 

 old joint lines seem to have been cemented or sealed, while layers of 

 rock in juxtaposition to the joint lines have been hardened, thereby 

 causing on weathered surfaces more or less angular figures (figs. G, S, 

 PI. 9, and P, PL 10). In the more siliceous rocks the old lines are 

 not so often cemented or sealed, but it is not uncommon even in 

 granites to find, adjoining to the joint lines, layers indurated, appa- 

 rently siKcified (fig. H, PL 9). 



Chlorityte, Talcyte. — These rocks seem to be very much allied, 

 as one rarely occurs without the other. Some were obseiwed to be 

 tourmalinic, others garnetiferous. They graduate into varieties of 

 micasyte and into hornblendyte. 



Felsityte. — This schist has, besides others, two marked varieties, 



* TufFose layers bet-ween flows or beds of plutonic rocks are foxiud in Cork, 

 Kerry, Limerick, and other places. 



