MAGMATIC DIFFERENTIATION OF IGNEOUS ROCKS 331 
TABLE I 
No. | SiO. | ALO; Fe.0; FeO ‘Meo CaO |Na.0} K:O | H.0 | Total 
Microcline Graphic Granite 
T../74.04|14.40| Nil Nil | Nil Jo. 33/2.01] 9.36] Nil |r00.18 
Norway........|| 2--|74-99/14.31 Nil Nil | Nil Jo. 39/2.42} 9.02] Nil |100.14 
3..173.82|14.44| Nil Nil | Nil Jo.35/2.45] 8.90} Nil] 99.96 
4../74.47|15.13| Nil ING PONDS os lls o colle owe 5 Bones tebe seat 
5. -173.70\04.11| Niall Nil | Nil Jo. 30/3.04] 8.72] Nil] 99-06 
Sweden......... [ ©. .\\72.anlta, sn ©2230 ...| Nil Jo.13]2.1q]10.09]/0. 28] 99.91 
7..|74.58|13.37| 0.24 |....] Nillo.32/1.16] 9.80]0.57|100.04 
8. .|73-89|13.75| 0.26 |....| Nil} Nil |2.10| 9.00]0. 24] 99.24 
United States... .|] 9--|73-92|14.26] 0.30 |....| Nil] Nil]2.06/ 8.99/0.11| 99.64 
% 10. .|72.76|15.44/(InAl,O,;)|....| Nil Jo. 19]2.35| 9.28/0.15|100.20 
II..|72.80]15.07] 0.26 |o.21| Nil} Nil |3.35] 7.92/0.30! 99.91 
Oligoclase Graphic Granite 
Womway.24.....|.12..|76.8 \r4.2 Nil NM ISM eo POs WeSS ooo OOS 
Swedenes 2. | .13../76.67|/14.20] 0.14 |..../0.04|/2.67|5.33/0.52 |o.48|100.04 
EXPLANATION 
Nos. 1-5 and 12, see “‘Silikatschmelzlés.,” II. No. 1 from Arendal; 
Nos. 2-3 from Hitteré; No. 4 from Raade; No. 5 from Arendal is industrially 
pulverized graphic-granite, in which a trifle surplus feldspar is not excluded. 
In all these analyses a small loss (0.1-0.3 per cent) caused by ignition is 
deducted. The precipitate of Al.O, was in all cases entirely white, and on 
account of this a special analysis of iron was not made. Some iron, less than 
©. per cent Fe,O;, is, however, not excluded. No. 12, approximate analysis 
from Evje. Nos. 1 and 5 were analyzed by A. Gronningsater and E. A. Dalset, 
assistants at the time. Nos. 2-4 and 6 were analyzed by students. K,0,Na.0 
and CaO in No. 4 have not been included on account of less accuracy. 
Nos. 6, 7, and 13 from A. Bygdén, Bull. of the Geol. Inst. of Upsala, Vol. 
VII (1906); from Elfkarleé, Skarpé, and Ytterby. 
Nos. 8-10 from Edson S. Bastin, U.S. Geol. Surv. Bull. 420 (1910); from 
Topsham, Me., and Redford, N.Y. (No. 10, a little Fe,O, [n.d.] in A1,O,.) 
No. 11 from Hiriart Hill, Cal., analyzed by W. T. Schaller, cited by H.S. Wash- 
ington, ‘Chemical Analysis of Igneous Rocks, 1884-1913,” U.S. Geol. Surv. 
Prof. Paper 99 (1907). (Cited below as Wash.) 
In the above table I have not included: Analysis of oligoclase graphic 
granite from the West Indies in Bygdén’s treatise (Wash., p. 267, No. 5, 
with 68.12 per cent SiO,), as this specimen is greatly decomposed, with con- 
siderable new-formed epidote, etc. This analysis can therefore not be used 
in the determination of the proportion of quartz and feldspar. 
Analysis No. 4 in E. S. Bastin’s treatise (Wash., p. 108, No. 4, with only 
71.00 per cent SiO,), as Bastin informs us of this specimen: “Some small 
