182 T. S. Hunt on Norite Rock. 
Prof. A. S. Packard, Jr., has given us valuable mformation 
with regard to the occurrence of labradorite rocks at some 
rere: on the Labrador coast.* One of its localities is at Square 
land, just north of Cape St. Michel, where the rock consists 
with a e vitreous quartz and with coarsely crystalline 
hy es which appears in relief on the weathered surfaces. 
o 
rounded by and probably rests upon Laurentian gneiss. At 
Domino Harbor he found domes or bosses of a similar labrador- 
ite resting upon strata which consist in great part of a slightly 
schistose quartzite, having for its base a granular vitreous quartz, 
ing, but in some parts these quartzites become gneissic, and 
was inclined to regard, in this 
= are prone nothing more than outlying portions of 
e newer Labrador i ia 
ks composed chiefly of labradorite or a related feldspar 
greatly predominate in the Labrador series, but these, at least 
in the area near Montreal, which is the one best known, are 
interstratified with beds of a kind of diabase in which dark 
green pyroxene prevails, with crystalline limestone similar 12 
mineralogical characters to that of the Laurentian system, and 
more rarely with quartzites and thin beds of orthoclase gneiss. 
I have more than once insisted upon the rarity of free quart 
and the general basic character of the rocks in this series, 22 
observation with which I am credited in Dana’s Manual of Geol- 
* On the Glacial phenomena of faine Acad. Nat 
ak, eh t pe eee. Labrador and Maine, ane Bost, e 
