QUARTZ-BEARING HYPERSTHENE-ANDESINE SYENITE 207 



its close resemblance in composition to Brogger's hypersthene akerite 16 

 from Barne Kjern See, Norway. The resemblance is admittedly close, 

 but unfortunately the analysis of the rock from the Norway locality is 

 rated by Washington 17 as inferior, and must be accounted therefore as 

 having but slight comparative value. 



For purposes of comparison we have selected the seven superior 

 analyses of akerites listed by Washington, one each from Massachusetts 

 and New York and five from Norway. 



Analyses of Akerites from Massachusetts, New York, and Norway 



I II III IV V VI VII 



SiO, 66.60 66.13 63.45 62.35 59.56 58.48 58.00 



ALA 15.05 17.40 IS. 31 19.50 17.60 19.24 16.91 



Fe 2 3 1.07 2.19 .42 3.05 2.90 5.75 3.29 



FeO 4.42 n. d. 3.56 2.25 3.38 n. d. 3.74 



MgO 36 .04 .35 1.46 1.87 .99 1.96 



CaO 2.21 .81 2.93 2.40 3.67 5.02 3.60 



Na 2 4.03 5.28 5.00 2.71 4.88 5.52 5.14 



K,0 5.42 5.60 5.15 3.28 4.40 3.06 5.20 



H,0— 41 1.22 ^ r .75 1.37 .47 .60 



H 2 0+ }- 30 { 



Ti0 2 76 .74 .07 1.25 1.22 .96 .85 



P 2 5 trace 



MnO trace .13 none .18 .03 trace .80 



BaO none 13 



100.33 99.54 99.73 99.18 101.32 99.41 100.09 



I. Akerite, Gloucester, Massachusetts. H. S. Washington, analyst. Journal 



of Geology, volume vi, 1898. page 798. 

 II. Akerite (porphyritic) between Thinghoud and Fjelebua, Norway. R. 



Mauzelius, analyst. W. C. Brogger : Zeitsch. f. Kryst., volume xvi, 



1890, page 46. 

 III. Augite syenite (akerite), Loon Lake, Franklin County. New York. E. W. 



Morley, analyst. H. P. Oushing : Bulletin of the Geological Society of 



America, volume 10, 1899, page 183. 

 IV. Akerite, Thinghoud, Norway. G. Sarnstrom, analyst. W. O. Brogger : 



Zeitsch. f. Kryst., volume xvi, 1890, page 46. 

 V. Syenite (akerite, W. O. B.), Vettakollen, n. Kristiania, Norway. P. Jann- 



asch, analyst. H. O. Lang : Nyt. Mag., volume xxx, 1884, page 40 ; see 



also W. C. Brogger : Zeitsch. f. Kryst., volume xvi, 1890. page 50. 

 VI. Akerite, Ramnas, Kristiania region, Norway. R. Mauzelius, analyst. 



W. C. Brogger : Zeitsch. f. Kryst., volume xvi, 1890, page 46. 

 VII. Akerite, Tuft, Laugendal, Norway. V. Schmelck, analyst. W. C. Brogger : 



Eg. Kg., volume ii, 1895, page 33. 



18 W. C. Brogger : Zeitsch. f. Kryst., vol. xvi, 1890, p. 50. 



17 H. S. Washington : Professional Paper No. 14, U. S. Geol. Survey, 1904, p. 389. 



