24 
MUSEUM BULLETIN NO. 4. 
The analysis of the tuff, column II, resembles that of the 
primary blairmorite, column I, in a marked degree, differing 
virtually only in the water content, and in the proportions 
of the alkalies. The difference almost certainly is caused by 
relatively more orthoclase in the tuff than in the primary rock. 
This close agreement in composition is another instance of the 
s nilarity obtaining between some of the pyroclastic rocks, 
in this suite, and their parents, a fact which has been referred 
to before. 
The other analyses given bear a marked resemblance to 
that of the blairmorite. 
The results of the calculation of the analysis of the blair- 
morite according to the Quantitative System is given below: — 
Class, persalane; order, lendofelic, russare; rang, peral- 
kalic, miaskase; subrang, dosodic near persodic, miaskose. 
The analysis of the analcite phenoerysts, which were easily 
obtained free from the enclosing matrix, is given below in column 
I with some other determinations of the composition of anal- 
cite for comparison. 
Analyses of Analcite . 
I 
II 
III 
IV 
V 
SiOj 
54-16 
54-39 
54*85 
57-06 
54*55 
TiOs 
0*15 
* « 
# , 
t m 
AlvDj ..... ... 
22-35 
22*08 
22-59 
21*48 
23*18 
FezO?. 
0-92 
2-85 
0-13 
FeO. . ... 
0-06 
• * 
* • 
m m 
MnO. ...... . 
trace 
a ■ 
• * 
MgO. 
0*25 
0*27 
* * 
CaO,. ... ..... 
0*60 
0*29 
0-89 
0*16 
NasO 
12-49 
11-75 
12-58 
12 20 
14-09 
R,0 
0-59 
1-03 
* • 
H s O+. ........ . 
8-50 
7-97 
9-06 
8-38 
8*18 
H*0 - . 
0-55 
, . 
0-58 
co a 
0-30 
• * 
* • 
100-37 
101*18 
99-97 
99-99 
100-00 
