544 



OGILVIE 



with acid igneous rocks and with mica schists in a very complex 

 way. As a rule the trend of the rock is the same as the strike of 

 the schistosity, but there are occasional exceptions. The way 

 in which it is caught in with other rocks is shown on the small 

 map of Cabbage Island. It was not put on the large map, 

 because the patches of it are so numerous and so small. There 

 are, however, several large and persistent streaks of the rock. 

 One of these is on Southport near Cape Newagen, where a band 

 of it is cut by a large diabase dike. Another very persistent 

 streak extended from near the head of Linekin's Bay northward 

 for about five miles. It was from this band that the chemical 

 analysis was made. 



Megascopic Character. — The rock is somewhat variable in color, 

 ranging from black to dark gray. In the black types horn- 

 blende is the only mineral distinguishable; in the gray, feldspar 

 and hornblende. The gray portions are very distinctly banded, 

 the bands consisting of alternating streaks of light and dark 

 minerals. The black and the gray portions both show fissility, 

 caused by a parallel orientation of the hornblende. 



Chemical Character. — It is evident that the chemical association 



is with the diabases, though the lime is higher than is usual; 



the potash lower; and the sum of the alkalies is low as compared 



with lime. 



Table IX. 





Analysis and Norm of M eta-auvergnose from Bayville, 



Maine. 



Composition. 



Molecular 

 Proportions 



Norm. 



Si0 2 







49.00% 



.816 



Qu 



.48 



A1 2 3 







15.46 



.152 



Or 



2.22 



Fe 2 2 







2.58 



.016 



Ab 



23.06 



FeO 







7.98 



.III 



An 



28.91 



MgO 







6.46 



.161 



Diop 



22.34 



CaO 







n.83 



.211 



Hyp 



n. 71 



Na 2 







2-75 



.044 



Mag 



3-7i 



K 2 







•44 



.004 



Ilm 



6.84 



H 2 + 







.09 





Ap 



.67 



H 2 0- 







.07 









co 2 







none 









Ti0 2 







3-72 



■045 







P 2 O s 



ital 





•3° 



.002 







Tc 



, 100.6.8 





