Till-: I'osT-rLiocENi:. 23 



mouths has no lateral motion ; it rises and (alls with the tide, but is 

 niiatfected by winds until the warmth of spring softens its hold on the 

 islands to wliieli it is keyed. When the pans are pressed on the 

 coast by winds, they accommodate themselves to all the sinuosities 

 of the shore line, and being pushed by the unfailing Arctic current, 

 which brings down a constant supply of floe ice, the pans rise over 

 all the low-lying parts of the islands, grinding and polishing exposed 

 shores, and ras[)ing those that are steep-to. The pans are shoved 

 over the flat surfaces of the islands, and remove with irresistible force 

 every ob tacle which opposes their thrust, for the attacks are con- 

 stantly renewed by the ceaseless ice-stream from the north-west, and 

 this goes on uninterru^itedly for a month or more. Sometimes a 

 change in the wind brings the endless sheet back again, and it is the 

 middle of July before some of the fiords are clear of ice. Hence 

 boulders, shingle, and beaches are rarely seen except in sheltered 

 nooks and coves, and the masses, pushed or torn from those surfaces 

 where cleavage offers a chance of disruption, are urged into the sea 

 and rounded into boulder form by the rasping and polishing pans." 



" Here too goes on the process, subsequently referred to, of manu- 

 facturing boulder clay, for the deep hollows and ravines at present 

 under the sea — the records of former glacial work — are being filled 

 with clay, sand, unworn and worn rock fragments, producing a 

 counterpart of some varieties of boulder clay." 



" But this is not all of the work of pau ice. The bottom of the sea, 

 to the depth of 12 or 15 feet, and at all less depths, is smoothed and 

 planed by the drifting masses when they pile one on the other, and 

 at depths less than 8 feet when the pans are driven before the wind 

 or carried by the currents. In sailing from Aillik to Nain or to Cape 

 Mugford, the fishermen send a man aloft to look out for " White 

 Rocks." These are prominences or swells in the general level of the 

 sea-bottom among the islands, from which every particle of sea-weed 

 has been removed by pan ice." 



" During a period of subsidence, the blocks of stone, boulders, 

 mud, and sand, pushed to and fro on tlie shallow sea-bottom by pan 

 ice, ultimately accumulate in hollows and ravines below its action ; 

 and when the debris is pushed into profound subnuxrine valleys, such 

 as exist on the Labrador coast (being probably due to former glacial 

 action), the mass will resemble boulder clays, and in a sinking 

 marine area it will accumulate to a great thickness ; in a rising area 

 it would be liable to be remodelled by the action of the waves except 

 in the case of very deep valleys, Tiicrc are m)t nnvny known narrow 

 and profound submarine valleys on the north- eastern coast of Labra- 



