192 
SUMMARY. 
The rocks from all the localities studied agree in certain | 
well-defined properties: — | 
i. They are certainly igneous in origin, and do not repre- 
sent highly metamorphosed sediments. | 
ii. The triclinic felspar is of remarkably uniform compo- | 
sition throughout. 
111. All show evidence of intense earth movements at some 
period of their history. 
iv. They are on the whole rather highly titaniferous. 
The evidences of movement are somewhat variable and are 
rather difficult to interpret as a whole. Pure albite is char- 
acteristic, not of eruptive, but of metamorphic, rocks. It is 
to be noted that in the rock which shows the least advanced 
degree of crushing, namely, the first described, the triclinic 
felspar contains some An. In the remaining rocks it ap- 
pears to be pure Ab. This seems to indicate a certain 
amount of molecular reconstruction. 
In some of the rocks cataclastic structures are common, but 
in others, particularly the most thoroughly foliated ones, 
shattering is not noticeable. In the latter case it would 
appear that the rock was plastic at the time the reconstruc- 
tion took place; that is, that it was at a sufficient depth 
below the surface to come into what Van Hise* has termed 
the zone of flowage. 
It is probable that the first rock described represents the 
least altered facies. 
The conclusion arrived at on page 189 with regard to the 
twinning of the albite is of interest if it is substantiated by 
other investigations. 
n E 
f 
* Van. Hise: “Some Principles Controlling Deposition of Ores,” 
Trans. Ann. Inst. Mining Engineers, vol. xxx., 1900, р. 31. 
