A. P. LOW — GLACIAL GEOLOGY OF LABRADOR AND QUEBEC. 421 



of James hay, the limestone being transported from the lower flat region about 

 the bay far inland over the higher interior Archean country. 



The retrocession of the glacier from the island moraine to the mainland i.s 

 marked by the morainic matter that fills the bay inside the boundary of the outer 



islands. 



Pleistocene Changes of Level in Labrador. — At the close of the glacial period there 

 was a marked elevation of the western part of Labrador. The extent and limits 

 of this elevation can be traced by the deposits of stratified sands and clays that 

 now cover the lower margin of the peninsula. On the Rupert and East Alain 

 rivers these deposits are found a long distance inland. On the latter river con- 

 tinuous deposits are met with for one hundred and ten miles from its mouth, and 

 at that distance reach an elevation of 050 feet above the present sea-level. 

 Although fossil marine shells are only found for some forty miles from the sea, 

 there is no d6ubt that the beds farther inland are a direct continuation of those 

 holding fossils and mark the limits of the ancient sea-level. As the exploration of 

 the Big river was not continuous, it is impossible to say to what distance inland 

 the marine deposits extend. For the first forty miles from its mouth the river 

 flows between steep banks of clay, capped with sand holding numerous fossils. 

 On the Great Whale river stratified deposits extend inland a distance of thirty 

 miles to beyond the forks. Above this the river passes for several miles through 

 a deep narrow gorge on its way down from the interior plateau. Any stratified 

 deposits which might have existed in this gorge have been washed away, and the 

 only traces of such are isolated patches of fine sand clinging to the rocky sides in 

 protected positions. The highest of these are about 100 feet above the river or, 

 roughly, 000 feet above the sea. Terraces up to 300 feet elevation flank the rocky 

 hills in a number of places along the northern coast. At the mouth of the Clear- 

 water river on Richmond gulf a series of fine sandy terraces are seen, the highest 

 being about 300 feet above the water. 



The first portage on the route from Richmond gulf to Clearwater lake passes up 

 a wide valley over old sea beaches facing the gulf; the highest of these on a level 

 with a small plain is 450 feet above the sea. Beyond this for ten miles up the 

 small stream followed by the route there are terraces cut in stratified clays and 

 sands that rise in the highest 160 feet above the river, or 075 feet above the present 

 sea-level. Beyond this line the surface material is unstratified till. 



From the above it will be seen that the Pleistocene elevation of the western side 

 of Labrador was nearly uniform from the south end of Hudson bay to Richmond 

 gulf, with a maximum elevation of (175 feet toward the north. 



According to Dr A. S. Packard,-- raised beaches and terraces are found along the 

 Atlantic coast from the strait of Belle Isle to Hopedale. These are seldom or 

 never more than 200 feet above the sea, or less than one-third of the elevation of 

 the terraces on the western side. 



If the theory that the greatest elevation conformed with the areas of greatest 

 ice accumulation, the ice-cap on the western part of Labrador must have been 

 much thicker than that on tin; eastern portion. This agrees with the state of 

 glaciation observed by Dr Bell t along the northern Atlantic coast, where lie re- 

 ports that the upper parts of the high Coast range form sharp serrated peaks, 

 covered with undisturbed rotted rock, and that evidence of glacial action is only 

 seen in their lower valleys. 



*The Labrador Coast, pp. 306-310. 



t Report of Progress, Geol. Surv. Canada, L882-'83-'84. 



