THE ANALCITE BASALTS OF SARDINIA 



751 



Sicily/ and the name of scanose has been given to it by me.^ The 

 Columbargiu rock falls in the subrang ornose, with the symbol 

 III. 5. (2) 3. (4) 5. The Bonorva rock has the symbol III. 6. i (2). 4. 

 This subrang, III. 6. 1.4, has been called pienarose by Brouwer,^ 

 but a recalculation of his analysis shows that the pienarite (aegirite 

 phonolite) described by him is really in III. 5. i. 4. The name 

 pienarose should therefore be applied to this subrang (III. 5. 1.4), 

 and the name pilandose may be given to III. 6. 1.4, in which falls 

 a Pilandsberg lujavrite described by him.^ 



TABLE III 



Norms of Analcite Basalts of Sardinia 



Mode. — -Owing to the very fine grain, the confused fabric, and 

 the presence of abundant glass, it is impracticable to determine the 

 mode by Rosiwal's method, and calculation of the mode by read- 

 justment of the norms is also subject to some uncertainty through 

 the presence of analcite. An attempt has, however, been made to 

 determine the modes by comparison of the several norms with the 

 respective thin sections, and checked by a Rosiwal measurement 

 of the analcite areas. The results are given in Table IV, but they 

 are to be regarded as only rough approximations. 



' G. Pontes, Atti Ac. Gioen. (5), III, No. X (1910), 7, 



- H. S. M'^ashington, C.R. XII Cong. G. Int., 1913. 



3 H. A. Brouwer, Traiisv. Nefel. syen. (1910), 50. 



^ Ibid., p. 132. This course has been decided on in conference with Drs. Cross 

 and Iddings. 



