and Igneous Rocks of Ensay. 



99 



developed and intact. I obtained some fairly satisfactory 

 measurements of the obscuration angles. Taking those 



which were in the zone OP — ooP oo, I had measurements 

 of 8° 30', 14°, 18°, 20°, and 30°, and there were four 



sections which were approximately in accordance with oo P oo, 

 in which the measurements were 14° 45', 15°, 16°, and 19°, 

 but two other similar sections gave me angles of 28° and 35°. 

 respectively. These angles cannot well indicate a felspar 

 more acid than a Labradorite. The crystals are compounded, 

 some after the Albite law, some after both it and the Carlsbad 

 law. In some individuals zonal growth is well shown. The 

 alteration of all these felspars is micaceous. 



Quartz is in considerable amount, and of the usual 

 character of that found in the massive holocrystalline quartz 

 diorites. 



The subjoined is a quantitative analysis of this rock : — 



Ti.0 2 



P 2 0. 



Si.O* 



A1. 2 3 



Fe. o 3 



Fe.O 



Ca.0 



Mg.O 



k?o 



Na. 2 

 HO 



No. 8. QuAETZ-MlCA DlORITE. 



•tr. 



•tr. 



6243 



17-88 



1-78 



353 



3-43 



4-50 



2-75 



3-10 



1-37 



100-77 



Hygroscopic moisture ... *315 

 Sp. grav. ... ... .., 2*74 



At this place the schists, which have been the special 

 objects of this paper, cease. That is to say, there are from 

 here onwards up the course of Watts Creek only here and 

 there traces of schistose rocks, the whole tract being 

 occupied with massive intrusive rocks. Of these I shall 

 note a few examples as illustrating this part of the section, 

 before proceeding to briefly note some rocks which occur 

 in the latter part before it terminates on the eastern side 

 of the Tambarra River. 



h2 



