F. D. Adams — Melilite-bearing Rock. 271 



tite is also present in small amount and can be separated from 

 the powdered rock by means of a magnet. Apatite as well as 

 perowskite, which is so constantly associated with melilite, is 

 found in small amount in all the sections, while a little nephe- 

 line is probably present intimately associated with the melilite. 

 Although some thirty-five thin sections have been prepared 

 and carefully studied, no feldspar could be detected as a con- 

 stituent of the rock. Curious angular fragments of a rather 

 coarsely crystalline rock, composed in some cases almost en- 

 tirely of plagioclase and in other cases of a granite or gneiss 

 are not uncommon as inclusions. These are bounded by 

 curious little contact zones and are evidently fragments of wall 

 rock which have been brought up by the molten rock proba- 

 bly from the underlying Laurentian. Cavities, partially or 

 completely filled with secondary minerals are also of frequent 

 occurrence. The specific gravity of three average specimens 

 of the rock was found to be as follows : 3 020, 3-013, 2 -955. 



For an analysis of the rock I am indebted to Mr. P. H. Le 

 Rossignol of this University. In order to obtain as far as pos- 

 sible an average, a large number of fragments were broken 

 from a series of the freshest hand specimens, and having been 

 reduced to powder the whole was carefully mixed together 

 and a portion taken for analysis. The results of the analysis 

 of this Alnoite from Ste. Anne are given under I below, while 

 under II the analysis of the melilite basalt from Hochbohl is 

 reproduced from Prof. Stelzner's paper* for purposes of com- 

 parison. No analysis of the rock from Alno has as yet been 

 published. 



I. II. 



Si0 2 _- 35-91 33-89 



TiO„ 0-23 0-64 



A1 2 3 ._ 11-51 9-93 



Fe 2 O s 2-35 15-63 



FeO_° 5-38 



CaO 13-57 15-19 



MgO 17-54 16-14 



K 2 2-87 



Na 2 1-75 2-86 



P„0 5 .'. not del. 1-41 



C0 2 ( 1-41 



ELO 1 ' 4U 2-90 



100-51 100-00 



The large amount of water and carbonic acid present in the 

 rock shows that even the freshest specimens have undergone 



* " Ueber Melilith unci jtfelilithbasalte," ISTeues Jahrbuch fur Mineralogie, etc., 

 1882, Beil. Bd. II. 398. 



