On the Norian or "Upper Laurentian" Formation. 417 



year 1882 and found the rock only in one place, where, 

 however, it formed a high cliff. The extent of this mass 

 is therefore not known, and for that reason its position 

 only is indicated on the accompanying map. 



It is to Packard that we are mostly indebted for our 

 present knowledge of the geology of the coast of Labra- 

 dor. In his memoir entitled " Observations on the Drift 

 Phenomena of Labrador and Maine," published in 1865, 

 he gives a general review of the geology of the southern 

 half of the east shore of the peninsula, which is repeated, 

 with a few trifling alterations, in his book entitled " The 

 Labrador Coast," published in 1891. In the latter he 

 gives a small geological sketch map. Speaking generally, 

 the peninsula of Labrador consists, as far as we know, of 

 Laurentian gneiss, with certain occurrences of eruptive 

 rocks. The gneiss has, generally, a rather granite-like 

 character, and probably belongs to the Lower Laurentian 

 or Ottawa gneiss. On the latter, however, there lies, in 

 a trough (almost 125 miles long by 25 miles wide, which 

 follows the coast all along from Domino harbour to Cape 

 Webuc), a series of beds of a light-coloured gneiss, rich 

 in quartz, better foliated, and often containing much 

 hornblende. Lieber called this rock the "Domino-gneiss." 

 A peculiar variety of trap is constantly found in con- 

 nection with this. Packard says that it represents a 

 higher, and probably an unconformable, group of Lauren- 

 tian rocks which correspond with the Grenville division 

 of the interior of Canada. 



Near Square Island, toward the southern end of the 

 coast, in the neighbourhood of the strait of Belle-Isle, 

 there occurs, along with the lower gneiss, a rock concern- 

 ing which Packard says : " There occurs in large conical 

 hills what I judge to be the great anorthosite formation 

 of Logan and Hunt, composed of large crystalline masses 

 of labradorite, with a little quartz, and coarse crystalline 



