H. C. Sargent — The Penmaenmaivr Intrusions. 27 



Analyses of Penmaenmawr Eock. 



IV. 



V. 



Sp. gr. 



2-771 



2-94 



2-79 



2-79 



2-840 



I. Compact marginal rock (GraigLwyd Quarry). Analysis by E. Sinkinson. 

 II. J. A. Phillips' No. i analysis. Fine-grained green rock from most 



westerly quarry. (Q.J.G.S., vol. xxiii, p. 424, 1877.) 

 III. J. A. Phillips' No. ii analysis. Moderately fine-grained rock from most 

 easterly quarry. Coarser than his No. i rock and less green. (Ibid.) 

 J. A. Phillips' No. iv analysis. Eock from second quarry from west ; 

 resembles his No. ii rock, but is coarser in grain and felspar more 

 extensively altered. (Ibid.) 

 Medium-grained rock from the centre of the mass. Analysis by 

 E. Sinkinson. 

 Note. — Phillips' No. iii analysis was of rock of about the same degree of 

 fineness as his No. i rock, and it had " evidently undergone more extensive 

 alteration". Its content of Si 2 was 62-24 per cent. (Op. cit., p. 425.) 



Analyses of Penmaenmawr Veins. 



99-79 



100-8 



99-74 



99-39 



Sp. gr. 



2-940 



2-72 



2-687 



2-945 



I. Green vein from near centre. Analysis by E. Sinkinson. 

 II. T. H. Waller. Grey vein from western quarries. (Midland Naturalist, 

 1885, p. 5.) . inAr 



III. L. Schaub. Grey vein. (Neues Jahrbuch fur Mmeralogie, etc., 1905, 



Abh. p. 113.) 

 IV. L. Schaub. Green vein. (Ibid., p. 118.) 



