92 RECONNAISSANCE IN NORTHERN ALASKA IN 1901. 



the ice layer i> about t> feet above the level of the sea. It goes south at least as far 

 as lev Cape without any decided break, and is found in different localities as far 

 south a- Kotzebue Sound.' At Point Harrow, near the international station, under 

 the direction of Lieut. P. H. Ray, P. S. Army, a shaft was sunk to a depth of 37 

 feet 6 inches, which passed through successive layers of mud, sand, and tine gravel, 

 with fragments of driftwood and marine shells, showing here and there large frag- 

 ments of pure fresh-water ice, but no continuous stratum of ice. The formation 

 here was clearly a beach alluvium, and relatively modern, a pair of Eskimo wooden 

 snow goggles with sinew string still attached to them being found at a depth of 27£ 

 feet. The temperature of the earth varied from —5° to +17.5° F. ; below the 

 influence of the external air the temperature of the earth was quite steady at 12° F. 

 for nine months. The earth was frozen and was extremely hard and tough. Blasts 

 put into the side of the shaft blew out without shattering the frozen earth around the 

 drill hole. It is probable that excavations farther inland might have revealed the 

 ice layer, which at the locality of the station did not exist." 



The observations made by the writer, while boating along the coast, lead to the 

 inference that the ground ice is not of so widespread occurrence as the above quota- 

 tion indicates. Between the Colville and Point Barrow the ice is possibly more or 

 less continuous along the coast, but of its inland extension we have little evidence. 

 Even along the coast it is not extensively exposed. Here long stretches of the low 

 tundra country are apparently underlain by rock or earthy deposit. 



Of the localities at which the ice was observed, the most important are Cape 

 Halkett and Cape Simpson, at each of which it seems to be practically continuous for 

 a distance of several miles. Cape Halkett, one of the most prominent promontories 

 along this part of the coast (PI. X, D), terminates in an ice cliff rising 30 feet above 

 tide level, and is overlain by a foot or two of muck, which in turn is carpeted by a 

 nap of moss and grass at the surface. Judging from topography, the ice at this 

 locality may extend inland several miles. Its thickness is not known, since its lower 

 limit lies below tide level. As shown in the view (PI. X, D), the cape is being rapidly 

 cut back by wave action, which undermines the cliff at tide level until by its own 

 weight the ice breaks off in large blocks and is ground up hj the surf. 



Coal occurs at Wainwright Inlet, between Point Barrow and Cape Beaufort. A 

 little southwest of that place the Jura-Cretaceous comes to the coast, and, judging 

 from topography, seems to continue nearly all the wa} r to Cape Beaufort, omitting 

 a probable breach at Icy Cape. From Cape Beaufort to Cape Lisburne rocks of 

 the Corwin series (Mesozoic) are known to be almost continuous. It therefore 

 seems, from the above facts, that the southern boundary of the ground-ice area repre- 

 sented on Doctor Dall's map should be shifted from the region of Icy Cape north- 

 ward, probably to at least beyond Wainwright Inlet, a distance of 60 to 75 miles. 



Of the Kowak clay containing Pleistocene vertebrate remains, referred to by 

 Doctor Dall in connection with the ground ice, but little was seen by the writer. 

 Observation, however, has been sufficient to suggest that, if present along the coast 



