and Igneous Hocks of Ensay. 95 



The marked feature of these rocks, as also of others of the 

 same class at Ensay, is the wasted and cavernous condition 

 of the felspars. 



31. — A massive, rather fine-grained, aplite occurs here. 

 It is composed of reddish felspar, quartz, and a little 

 magnesia-mica. It is traversed by east and west joints. 

 Following it, and continuing up to 32, are coarsely foliated 

 schists, with pinite. The partings of these rocks strike N. 

 20° W., and in places the schistose structure is very evident. 



At 33 there is an outcrop of rocks which, it seemed to 

 me, fairly represent the most completely metamorphosed 

 schists in this part of Watts Creek, in which not only the 

 sedimentary but also the more foliated schistose structure 

 has been obliterated. 



I found it to be composed of large felspars, mica, and 

 quartz. The felspars are of two varieties. One is in large, 

 ill-formed crystals, or, more properly, crystalline masses, in 

 which the obscuration indicated orthoclase. One instance 

 had veinlets of a second felspar included in it, as is the case 

 with orthoclase perthites. These felspars are not uniformly 

 altered, being in places kaolinised, and in others converted 

 more or less into pinite and mica. 



The other felspar is in smaller and more perfectly deve- 

 loped crystals. It is very compound, and the obscuration 

 angles which I could measure I found to be in the zone 



OP — oo P oo between 1° 45' and 16° 30', suggestive of 

 oligoclase. 



The magnesia-mica is almost wholly chloritised, and it is 

 associated with rounded, or nearly rectangular, pinite 

 pseudomorphs. Alkali-mica is also present, accompanying 

 the pinite. 



The quartz is residual, filling in spaces, in rather large 

 interlocking grains. 



The microscopic examination of this rock shows that its 

 features are those rather of the massive schists than of the 

 intrusive rocks. The orthoclase felspars resemble those of 

 the pegmatite contact veins ; the magnesia-mica is poorer 

 in iron than that of the intrusive rocks which I have 

 examined, and the pinite pseudomorphs are just such as 

 those I have already described. 



Rocks which are somewhat more distinctly schistose 

 extend to 34 on a strike north, where they again become 

 more massive, and adjoin aplites. 



