Dr. G. M. Daicsons Annual Report. 523 



Peninsula along tbe East Main, Koksnak, Hamilton, Manicuagan, 

 and portions of other rivers, in 1892-5. Mention is made of the 

 sources of information about the historj?-, physical geography, and 

 natural history of the region exploited ; acknowledgment is made of 

 kind help and hospitality given by officers of the Hudson Bay 

 Company ; and the work of colleagues and assistants is carefully 

 recorded. The elaborate chronological account of previous dis- 

 coveries and explorations (pp. 7-19) is of great interest ; it extends 

 from 990 to 1891. The physical geography, climate, soil, trees 

 and other plants, the population, and fisheries, are successively 

 dealt with. Detailed descriptions of the routes explored follow 

 (pp. 56-195). The observations by Mr. Low and the Assistant 

 Surveyors on the geological structure of the great territory under 

 notice were made along widely separated lines of exploration, but 

 afford the means of making an approximate estimate of the distribu- 

 tion and extent of the areas of the different rocks, their mutual 

 relationship, modes of occurrence, and relative age ; also of their 

 economic materials, and of the features and conditions of surface due 

 to glacial action (pp. 195-311). 



" The term ' Laurentian ' is employed to designate the complex 

 mass of highly crystalline Archaean rocks of which the greater part 

 of the Labrador Peninsula is composed. These do not differ in any 

 essential particulars from those similarly designated in other parts 

 of Canada. They consist chiefly of gneisses and schists, some of 

 which are believed to be highly metamorphosed materials of clastic 

 origin, while others are regarded as foliated eruptives. As it is not 

 possible, except in limited areas, to separate these rocks on the map, 



they are necessarily treated together Under the name 



' Huronian ' are included several widely separated areas of clastic 

 and volcanic rocks, together with many basic eruptives ; these are 

 represented by various schists, conglomerates, bi'eccias, diorites, and 

 other rocks more or less interfolded with the Laurentian. 



" The Cambrian rocks rest unconformably upon the Laurentian 

 and Huronian, and are made up of bedded sandstones, argillites, 

 shales, and limestones, along with bedded traps and other basic 

 intrusive and volcanic rocks 



" The Laurentian and Huronian gneisses and schists are intensely 

 folded. This folding took place long previous to the deposition of 

 the sedimentary beds of Cambrian age; and a sufficiently long time 

 had elapsed between the period of folding and the Cambrian sub- 

 mergence to allow for great removals of material by denudation, and 



for the main sculpturing of the Peninsula The enormous 



lapse of time requisite for the formation of the Hamilton inlet and 

 river-valley can hardly be conceived if the denudation was not much 

 greater than that under present conditions." 



We may note that " the anorthosite is a variety of gabbro, made 

 up of labradorite, holding isolated masses of hypersthene or rhombic 

 pyroxene, ilmenite, and mica. In texture it varies from exceedingly 

 coHrse, with crystalline faces sometimes nine by six inches, to a fine- 

 grauied saccharoidal form. The colour is generally a shade of violet, 



