and Igneous Rocks of Ensay, 71 



This quartz contains very numerous fluid cavities without 

 bubbles. 



This rock has been so much crushed and contorted that 

 the foliations are in places reverted over each other. 



The second variety which I examined I found to be much 

 more complex, and to show changes approaching to the 

 condition of a minutely -foliated gneiss. The proportion 

 between the quartz and the other component minerals is 

 much more equal in this than in the last-described example. 

 The rock is foliated, and the main part consists of micaceous 

 materials mixed with quartz grains and enclosing minute 

 crystals, which can scarcely be anything else than orthoclase ; 

 at any rate, they are not andalusite. 



There are also some minute pinite pseuclomorphs after this 

 felspar. The quartz occurs in very numerous interlock- 

 ing granules, which form foliations, and also veins, branch- 

 ing from one to the other across the micaceous foliations. 



These rocks, although still bearing much the outward 

 appearance of sediments, prove upon microscopic examina- 

 tion to have been so altered as to be almost within the 

 bounds of the group of metamorphic schists of Ensay. 



The only other remaining traces of rocks which can be 

 referred to the less altered sediments rather than to the 

 schists are at the sources of the Watts Creek, or rather, to be 

 more correct, a little beyond them, where the track from 

 Ensay to Gellingall crosses a small stream before rising on to 

 the divide which falls to the Wilkinson River, I could not 

 find these rocks in situ, but only as fragments in the bed of 

 the stream, the sides of the hills being there covered with 

 soil. So far as I am able to judge, I think that these sedi- 

 ments adjoin a diabase mass on the west side, and may 

 therefore have been subject to two separate metamorphisms — 

 first, in common with all the sediments of the district, and 

 second,, by the diabase. 



The samples in this instance represent, as elsewhere, the 

 argillaceous and the arenaceous sediments, and I now give 

 the results of their examination. 



The first example consists mainly of a micaceous mineral, 

 having a fibrous structure, and thus resembling sericite-mica 

 in appearance and in its reaction with polarised light. It is 

 colourless, or of a pale greenish tint, where not stained by 

 iron ochre. In some of the foliations the small masses have 

 their fibres parallel to each other, whilst in others they are 

 twisted and lie across each other in a felted manner. In 



