286 Canadian Record of Science. 



from white granular limestone, if, as is generally the case, 

 it is almost pure plagioelase. 



The peculiar white granular variety of the anorthosite 

 with comparatively few large individuals, forms in the 

 Morin area, the greater part of the above mentioned arm- 

 like extension at its south-east corner. In this the anor- 

 thosite protrudes from the drift in every direction in 

 hundreds of smooth white bosses, which give a very 

 peculiar appearance to the country. It is also met with 

 and largely developed in the Saguenay area and other 

 anorthosite areas in the Province of Quebec. It was 

 furthermore described by Dr. Albert Leeds 1 as occurring in 

 the county of Essex, New York ; by Vogelsang 2 in 

 Labrador, as well as by other observers, and may therefore 

 be considered as being present to a certain extent in most 

 of the areas of this kind of rock. In the Morin anor- 

 thosite area (and the same applies to the Saguenay area), 

 we find the most granular varieties near the sides and 

 especially on the east side, as if the pressure had been 

 exerted from that direction. In the arm-like extension of 

 the Morin area, this fine granular variety is quite clearly 

 seen, and since the district is easily accessible by roads and 

 pathways, its structure and other characters may be 

 studied with comparative ease. This arm has an average 

 breadth of nearly six miles, and is of a nearly equal width 

 throughout. At the southern end. before it is covered by 

 the unconformable Cambrian beds, it becomes a little 

 broader, owing to the fact that it has been split longi- 

 tudinally by a wedge of gneiss. As has been already 

 mentioned, it runs into the gneiss parallel to the stratifi- 

 cation or foliation of the latter, so that it appears here as 

 if it formed an instratified layer. 



The white granular anorthosite, moreover, is in this off- 



i A. Leeds, Notes upon the Lithology of the Adirondacks. 13th Annual Report of 

 the New York State Museum of Nat. Hist., 1876. 



2 Vogelsang, Sur la Labradorite coloriee de la Cote du Labrador, Archives Neerlan- 

 daisesIII, 1868. 



