184 CONTRIBUTIONS TO THE GEOLOGY OF MAINE. [bull. 165. 
I. Teschenite from Mapleton Township, Aroostook County, Maine. Analysis by Dr. W. F. Hille- 
brand, United States Geological Survey. 
II. Theralite from Gordons Butte, Crazy Mountains, Montana. Analysis by E. A. Schneider, 
Bull. U. S. Geol. Survey No. 148, 1897, p. 146. 
III. Theralite from Gordons Butte. Another sample of II. Analysis by Schneider. 
IV. Theralite, north of Alabaugh Creek, Crazy Mountains, Montana. Analysis by E. A. Sohneider 
Bull. U. S. Geol. Survey No. 148, 1897, p. 146. 
V. Teschenite from Boguschowitz, Silesia. Analysis by Tschermak, Teschermaks Min. mid Petrog. 
Mittb., Vol. VI, 1885-86, p. 42. 
VI. Augite-teschenite, Point Sal, California. Analysis by H. W. Fairbanks. Fairbanks, Geology 
of Point Sal: Bull. Dept. Geol. Univ. California, Vol. II, 1896, No. 1, p. 31. 
VII. Monchiquite, Brazil. Analysis by Hunter, Tschermaks Min. und Petrog. Mitth., Vol. XI, 
1890, p. 464. 
VIII. Essexite from Salem Neck, Massachusetts. Analysis by H. S. Washington. Washington, Petro- 
graphical Province of Essex County: Jour. Geol., Vol. VII, 1899, No. 1, p. 57. 
Discussion of analysis. — An inspection of the analysis (I) shows 
that there is not enough ferric oxide to convert the titanium dioxide 
and ferrous oxide into iron ore, and it is probable that part of the 
titanium dioxide is present in the augite, as would be expected from 
its violet color. It is evident that the soda and potash could not be 
converted into feldspar without forming a variety much richer in soda 
than the analysis shows. Perhaps soda orthoclase is present, but it 
seems quite certain that there is also some sodium aluminate com- 
pound besides feldspar in the rock. Furthermore, the amount of 
silica present is not sufficient to convert the potash, soda, and lime 
into feldspars, and some feldspathoid w T ould be formed; this was most 
likely nepheline. Some of the analcite present is certainly secondary, 
and it is quite probable that it all is so. 
Comparison of the analyses in the table given above will show the 
close relationship between the Maine rock and the typical theralites, 
and it is very probable that the former was a theralite in its original 
condition. 
In regard to the essexite (VIII), Dr. Washington says that " nephe- 
line is fairly abundant, generally interstitial, but occasionally in well- 
shaped crystals." 1 This fact, together with the closely similar chem- 
ical composition, goes to show how closely related are the members of 
the theralite-essexite-teschenite series. 
GRANULAR TYPE. 
Macroscopic description. — The same minerals are found in this tp}^e 
as in the coarsely crystalline, but their form, relative abundance, and 
method of arrangement are different. In the hand specimen no distinct 
crystals are seen and the rock appears more as a fine, even-grained, 
brown sandstone. The areas where this type occur are very different 
in appearance from the other parts of the large dike, but are not sep- 
arated by any distinct boundaries. The specimen from lot 100 has the 
character of a fine-grained lamprophyre. 
1 Jour. Geol., 1899, Vol. VII, No. 1, p. 54. 
