DALY: GEOLOGY OF THE NORTHEAST COAST OF LABRADOR. 241 
also aligned in series. In both cases the axis of symmetry and the 
convex side of the curved pit were directed N. 55°-60° E. What made 
this locality of particular interest was the fact that one series of seven 
furrows lay on the stoss side of a ledge covered with undoubted glacial 
strie and grooves. These were seen to lie in the axis of the lunes. 
The trend of the strize was likewise N. 55°-60° E. Such a relation of 
parallelism between lune-axes and striz was a strong witness to the 
glacial origin of the lunes, and it was found to exist in the.case of the 
great majority of them at each locality on the coast. (See Table IT.) 
The best exposures of the lunes discovered during the summer are at 
Pomiadluk Point, at Aillik Bay and at Hopedale. (Plate 7.) At the head 
of Aillik Bay near the highest of the elevated shore-lines, a fine group 
of naked, highly polished roches moutonnées are marked with numerous 
lunes from two to three feet in span. On the east side of the bay at the 
shore near the prominent trap dikes opposite Summer Cove, the serial 
arrangement of the lunes is exceptionally well developed. In one 
instance twelve, and in another fifteen, of them were seen in line. 
Single lunes, very rarely ]unes grouped in series, are sometimes so 
situated that their axes of symmetry are widely divergent from the 
accompanying lines of striation. Such an attitude is, however, quite 
exceptional, and in general, the perfection of the lunate form is greatest 
when the axis of symmetry is orientated parallel to the striz and 
grooves. Like the latter, the lunes were found most commonly on the 
stoss side of the glaciated ledge. As in Maine, the convex side of the 
lune is always directed downstream with reference to the moving ice- 
sheet that formed the grooves. This is true in the south and also at 
Nachvak where the glaciation was but local. 
There seems to be no reasonable interpretation of the lunes that does 
not assign their location to glacial action. But it is difficult to imagine 
how either clean ice or boulders caught in the ice and dragged over a 
ledge could produce the actual furrow. From a somewhat prolonged 
study of the typical examples at Hopedale, the writer was led to believe 
that these lunes were only potential when the ice-sheet disappeared and 
to extend the same idea to all such furrows. The tension or shearing 
stress set up in the bed-rock by a boulder dragged along beneath the 
ice, must oftentimes be enormous. This must be so if boulders are 
really responsible for the deep striation and grooving of glaciated ledges. 
Such shearing stress may be easily conceived to be here and there partly 
relieved by the development of incipient cracks dipping gently forward 
and, at the same time, sloping inward from each side toward the line 
