GEOLOGICAL OBSERVATIONS 



above sea-level. It is usually in the form of a flat narrow 

 terrace from 20 to 100 ft. wide, sometimes in that of a 

 sheer cliff, occasionally as much as 80 ft. to over 100 ft. in 

 height, the summit of which ascends inland in a more or 

 less steep snow slope. At its base, in summer, the ice-foot 

 is almost invariably undercut by the sea, and from the 

 overhanging roof thus produced there depend vast 

 numbers of beautiful icicles. These icicles have, of course, 

 been formed from the wash of the waves, and the sea 

 water in the process of being frozen has extruded its 

 brine, the salinity of which is such that the solution cannot 

 freeze at a temperature above zero Fahr. These icicles are 

 generally moist, and the moisture, in the form of con- 

 centrated brine, works downwards, under the influence 

 of gravity, to the tips of the icicles, which thus become 

 sticky. Hence when a blizzard springs up and drives 

 snowflakes against them, the flakes stick on chiefly at 

 the tips and gradually build out those foot-like struc- 

 tures which we have termed foot-stalactites, and which are 

 illustrated. 



During the winter of 1908 and the succeeding spring 

 and summer, we were able to see clearly the mode of 

 growth of the ice-foot. After the sea surface had been 

 frozen over snow carried by the wind from the land, or 

 from the surface of the Great Ice Barrier formed drifts 

 of greater or less thickness over the sea ice close inshore. 

 These, at their shoreward end where the cliff's are 80 or 

 100 ft. in height, may form drifts of equal thickness with 

 the height of the cliff*. These drifts, of course, thin out 

 seawards. They are stratified and contain numerous dark 

 bands formed of chips of rock, broken crystals of felspar, 

 &c. When, during the summer, strong blizzards disrupt 

 the sea ice, large rafts of ice are dislodged from near the 

 shore, and these carry away on their surfaces portions of 

 the old sno"W-drifts. As the work o^f destruction ptdceeds 



