REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 r85 



General description of the exposures 



Kear the depot and in the village the rock is more typically 

 syenite than elsewhere. Though the body of the rock is 

 thoroughly granulated, well foliated and with an excellent cleav- 

 age, augen abound, reach a larger size than elsewhere, and the 

 rock as a whole is more homogeneous. It has a gray, or greenish 

 gray color, while the feldspar augen are dark and, except for the 

 absence of twinning etriations, strongly suggest labradorite. In 

 the more gneissoid portions the augen are alined w^ith their long 

 axes parallel to the foliation, and the cleavage planes run around 

 them, giving a pseudo-flow structure effect. 



The general syenite here is quite acid and quartzose (nos. 1, 2, 

 3).^ It also varies locally to a reddish, more acid rock (no. 4), 

 which would seem clearly a granite, though it has not been 

 analyzed. All of this rock seen was even more thoroughly granu- 

 lated and gneissoid than the ordinary syenite, though still show- 

 ing occasional augen of red feldspar. In both rocks hornblende 

 is the prevailing dark silicate, but the red rock holds much less 

 of it than the other, and consists mainly of quartz and feldspar. 

 These are how^ever quite thoroughly separated and the cleavage 

 is surprisingly well marked and even. 



Locally here in the west end of the section the rock has been 

 thoroughly reddened by infiltration of ferric oxid, w^hich has 

 worked its way along the joints into the cleavage planes, thence 

 around the finely granular material and even into the cleavage 

 cracks of the feldspar augen (no. 5). The boundary bet ween the 

 reddened and the unaffected rock is often of the sharpest sort, 

 simulating an intrusive contact. Often little films or sheets of 

 the red color extend out into the ordinary rock, sometimes across 

 and sometimes along the cleavage planes, often mimicking 

 remarkably the penetration of schist by granite. 



Going east from the village along the railway, whose rock cut 

 has a steep up grade, the coarse acid syenite is found passing 

 into a finer and more basic rock, and such constitutes most of the 



^ The numbers are those borne by the specimens collected, now on 

 deposit in the state museum. 



