HOT WATER SUPPLY OF THE HOT SPRINGS 443 



throw and recent age. This association seems a definite indication 

 of juvenile origin. Hot springs in volcanic regions are probably 

 in part of mixed origin. The presence of uncooled or even molten 

 rock near the surface makes easy the heating of meteoric water 

 and its return to the surface. Doubtless some springs in volcanic 

 regions have a wholly meteoric origin, as Hague' has proposed for 

 the geysers of the Yellowstone. Yet beneath volcanoes magmas 

 are crystallizing and expelling water. It is inconceivable that all 

 of this water is absorbed in chemical reactions or in the interstices 

 of the rocks below the surface. Some of it, with its contained 

 minerals and gases, must reach the surface. 



Springs with steady flow and without great variations in 

 temperature or quantity, especially if they are hot, must then arise 

 from some deep artesian circulation or be of juvenile origin. The 

 artesian circulation should be susceptible of proof on structural 

 grounds. In the absence of such proof the indication of juvenile 

 origin is very strong. 



Elaborate investigations of the chemical characteristics of 

 water, with the object of discovering its origin, have so far proved 

 disappointing. Sodium chloride and sodium carbonate waters 

 from granitic rocks carry a strong presumption of juvenile origin 

 since the ordinary springs of such regions have water of the calcium 

 carbonate type.^ But unusual substances such as boron and 

 fluorine have been found in spring waters of such diverse types as 

 to be without critical value. 



ANALYSIS OF THE MERITS OF THE HYPOTHESES 



The question of the ultimate origin of the water in the Hot 

 Springs of Arkansas is not only of intense theoretical interest, but 

 has practical bearings. If the water is juvenile there is presumably 

 a constant supply, diminishing very gradually through the centuries 

 in quantity and temperature. When all the water is conserved 

 by adequate structures it is probable that no more can be obtained. 

 If, on the other hand, the water has a meteoric origin, it is variable 



' Arnold Hague, "Origin of the Thermal Waters in the Yellowstone National 

 Park," Bull. Geol. Soc, Vol. XXII (191 1), pp. 101-22. 

 ^ W. Lindgren, op. cit., p. 64. 



