HENRY S. WASHINGTON 



rocks containing these are called " leucite-syenite," "leucite- 

 eleolite-syenite" and " leucite-phonolite " by Rosenbusch and 

 Zirkel, it would seem to be justifiable, at least for the present, to 

 speak of the Kula rocks as hornblende-bearing. 



The analyses I and III calculate out very sharply as shown 

 in the table below, with results worth commenting on. In the 



Anorthite 



Albite 



Orthoclase 



Leucite 



Nepheline 



Diopside 



Olivine 



Magnetite 



Apatite - 



Water, etc. 



first place this calculation confirms the observation that nephe 

 line is present, as there is too much Na g O or too little Si0 3 to 

 satisfy each other on any other basis. 



It is also of interest to note that, although these rocks are so 

 basic in composition, and so basaltic in general habit and appear- 

 ance, yet the feldspars and feldspathoids constitute over 70 per 

 cent, of the mass, and that they consequently are leucocratic, to 

 use the distinction into two groups recently given by Brogger. 2 

 So little is known of the rocks of Asia Minor that as yet no 

 melanocratic complements of these are positively known, though 

 it is to be expected that they will be discovered some time in 

 this petrographic province. 



It will be noticed that in I the plagioclase is a bytownite of 

 the composition Ab An 4 , while in II it is an andesine, approxi- 

 mately Ab 3 An 2 . It is certainly remarkable that in the one 



1 Inasmuch as diopside, hornblende, hypersthene and olivine are present together 

 in III, it is impossible to calculate the exact relative amounts of each, and the analysis 

 has, therefore, been calculated on the assumption that only diopside and olivine are 

 present. The error involved will not be large, as the hornblende tends to alter to a 

 mixture of diopside and magnetite. 



2 Brogger: Erupt, gest. d. Kristianiageb, III, p. 263, 1898. 



