and Igneous Rocks of Ensay. 77 



in places, straight obscuration, but the crystals do not obscure 

 homogeneously, but in different parts successively. In the 

 basal section of these felspars I observed numerous minute 

 wedge-shaped crystals, arranged parallel, and perpendicular 

 to the plane of symmetry. The larger ones I could see were 

 twinned, and in places groups of these crystals suggested 

 the grated appearance of microcline. As inclusions, there are 

 also a few crystals of triclinic felspar and grains of quartz. 

 These latter have rounded sides, and have much the appear- 

 ance of pre-existing crystals enclosed in the felspar. 



The quartz is in large masses, and is full of minute fluid 

 cavities massed together or in layers. 



The only other constituent is a colourless alkali-mica in 

 small amount when compared with the quartz and felspar. 

 Rarely it occurs in the felspar itself. 



The schists, which recommence at 3, and extend thence 

 to 4, are very characteristic. In saying that they are 

 schistose, it must not be supposed that the foliations are 

 either wide or strongly marked. On the contrary, in all the 

 rocks of this kind the foliations are often very narrow, and 

 only indicated to the eye by irregular stripes, differing 

 from each other more or less in colour. The rock thus 

 resembles in appearance some of the schistose varieties of 

 hornfels. These remarks apply, however, only to the 

 foliations of the mass of the rock, which seem to represent 

 the original planes of deposition; and I may here note 

 that where I found these foliations most regular they had a 

 strike near that of the normal sediments of the district, 

 They do not apply to the foliations of quartz or of crystalline- 

 granular texture, which are a marked feature here. The term 

 foliation is indeed often inapplicable to these, for I have 

 observed that they frequently run, not only with the 

 foliations of the rock, but also across them at all angles. 

 The quartz veins are just such as are so commonly to be seen 

 in the Omeo district in places where there is a passage from 

 the sediments to the schists, and I have now come to look 

 upon them as an unfailing indication of metamorphic altera- 

 tions. The veins of crystalline-granular materials are more 

 irregular than those of quartz. They not only run with or 

 across the foliations, but also appear as isolated masses in 

 them. No doubt this appearance of isolation may lead to 

 the belief that portions of the schists have suffered complete 

 metamorphism and recrystallisation, but I am now confident 

 that such is not a true explanation of those cases, at least, 



