STRUCTURAL GEOLOGY. 37 



The Kekequabic granite.] 



many as twenty. The rock is here represented by No. 594G, and pebbles from it by No. 594aG. This rock 

 extends along the shore in a few outcrops nearly to the east line of section 31. The pebbles grow less abundant 

 on going east from No. 594G. No. 595G shows a more highly crystalline condition of this rock from the S. E. % 

 N. E. J4 sec. 31. The noticeable features of this rock are its sharply outlined, rounded and sub-angular pebbles 

 and the few scattering, white, apparently porphyritic, feldspar crystals, sometimes a quarter of an inch in length. 

 No bedding, lamination or definite arrangement of the pebbles could be seen in the rock. It seems that this rock 

 is a metamorphosed conglomerate, and it strongly reminds one of certain facies of the Ogishke conglomerate. 



In making, subsequently, a microscopic study of this rock it was classed as a 

 hornblendic facies of the granite,* with the following note: 



What is termed the hornblendic facies of the granite is found only in a narrow strip along the south shore 

 of Kekequabic lake in sec. 31, T. 65 N., R. 6 W. It has a fine grained gray groundmass whose constituent 

 minerals are not readily distinguishable. In this are usually scattered small whitish subporphyritic feldspars 

 and less evident black prisms of hornblende. This rock is different from the main mass of the granite in 

 several respects, and the writer does not feel entirely satisfied that it is part of the granite, but it seems to be 

 such and is placed here as a hornblende facies of the granite. 



This rock (No. 595G) consists mostly of feldspar showing the usual characters, 

 I. c., much twinned with coarse and fine bands, often of tapering widths (albite and 

 pericline), of hornblende, quartz and epidote. There is also a little biotite and mag- 

 netite. The hornblendes were at first augite, as shown by the central residua of 

 greater absorptive power. The original feldspars were often nearly complete as 

 crystals, but for the most part are fragments, and are clouded with fine epidote. 

 They are cemented together by secondary deposition of fresh feldspar and of quartz. 

 As grains they never interlock with one another. 



A still more evident fragmental condition of a " porphyry," or porphyrel, is to 

 be seen at Zeta lake, about a mile east of Kekequabic lake, where feldspar crystals 

 as clastic elements are liberally mingled with pebbles of various kinds. There is, 

 according to Dr. Grant, a traceable connection of this rock with the pebbly granite 

 of the south shore of Kekequabic lake. In all respects, except in having a more 

 evident fragmental composition, it is also a repetition of the porphyritic phase of the 

 granite of Kekequabic lake (compare No. 1061, from Kekequabic lake with No. 1062 

 from Zeta lake). This porphyrel at Zeta lake has much the appearance of an igneous 

 rock. It is in massive knobs that present a bold rounded outline quite similar to 

 the porphyry at Kekequabic lake. It has a coarse jointage giving it a basaltic' 

 structure, and it was only after considerable field examination, and the consider- 

 ation of the screened, though evident, pebbly structure that this rock was, in the 

 field, recognized as a fragmental one. It is an obvious inference to unite this with 

 the pebbly granite described by Dr. Grant, in a series which passes onto non-pebbly 

 granite, and with the porphyry knobs at Kekequabic lake, which are less pebbly. 



Order of generation of the neic minerals. In the process of transformation from 

 a clastic to a granite, at Kekequabic lake, the minerals appeared in the following order: 



1. Actinolite, or hornblende, is formed, if it did not already exist, in the clastic 

 rock. This was accompanied by a micro-granulation of the old feldspars, and by a 



* Annual Report, xxi, p. 40. 



