Ocean Currents 



135 



assistant geologist, will be in charge, 

 and will be accompanied by two men. 

 Mr. Collier will start at the interna- 

 tional boundary and carefully study 

 the Yukon section as far as the delta. 

 He will make special investigation of 

 such areas as are known to contain 

 coal. He will also visit some of the 

 placer camps accessible from the river 

 which have not yet been investigated. 

 This work is of particular importance 

 from the standpoint of geologic corre- 

 lation. Mr. Collier will have ample 

 time to study the geologic relations in 

 detail and to collect paleontologic data. 

 It is believed that his work will throw 

 considerable light on some of the broader 

 stratigraphic problems of the territory. 

 Southeastern Alaska, embracing an 

 area of about twenty thousand square 

 miles, presents problems entirely dif- 

 ferent from those of the interior. The 

 Coast and Geodetic Survey has com- 

 pleted the reconnaissance surveys of the 

 coast line, but its detailed topographic 

 work is limited to a few areas. As the 

 mineral resources, consisting of gold, 

 copper, silver, and nickel, occur in _de- 

 posits which require large expendi- 

 tures for underground mining, reduc- 

 tion works, etc., it is necessary, in this 

 region, to carry on investigations in 

 great detail, if they are to be of value 



to the mine-owners and prospectors. 

 While the question of transportation is 

 here much simplified because of the 

 natural waterways, yet the dense timber 

 and the heavy rainfall of the summer 

 season make work in this region so diffi- 

 cult as to greatly increase the cost. 

 Unless the appropriations are increased, 

 it will take many years to map the most 

 important mining districts alone. The 

 Geological Survey, therefore, proposes 

 to begin- this work by mapping the 

 Juneau mining district this year as a 

 base for future detailed geologic studies. 

 This topographic work will be in charge 

 of Mr. W. J. Peters. The Juneau dis- 

 trict is the tnost important in all Alaska, 

 containing, as it does, the famous Tread- 

 well mine. 



We have a territory of nearly six 

 hundred thousand square miles, and of 

 this less than a sixth has been surveyed. 

 These surveys have been chiefly of a 

 reconnaissance character, and must be 

 followed by mapping in greater detail. 

 In view of the rapid development of the 

 mineral resources, the immediate com- 

 pletion of the reconnaissance surveys 

 •and the initiation of the detailed surveys 

 are a crying need. There would seem 

 to be economy in such immediate fur- 

 therance of the important mining in- 

 terests of Alaska. 



OCEAN CURRENTS 



By James Page, U. S. Hydrographic Office 



EVERY method of investigation 

 thus far employed, whether the 

 drift of floating objects, the 

 comparison of the temperature and 

 specific gravity of specimens drawn from 

 widely distant points, the distribution 

 of animal organisms inhabiting different 

 localities, all lend support to the belief 



that the vast mass of the surface water 

 of the sea, and of the water some depth 

 below the surface, even at a distance 

 of thousands of miles from the conti- 

 nental shores, and hence far removed 

 from local or tidal-current influence, is 

 in motion ; and the continuity of this 

 motion, in certain broad and well-de- 



