THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. XV.— The Saltan Sea;* by Db. D. T. MacDougal. 



Extensive basins occur in various parts of North America, 

 Australia, Africa, and Asia, in which the climatic and hydro- 

 graphic conditions are such that the lowermost parts of the 

 depressions are at times occupied by bodies of water, which 

 may disappear or show wide fluctuations of level or volume. 

 Alternations of this kind are followed, of course, by the 

 annihilation of the terrestrial vegetation, as lakes are formed 

 or as they increase, and by the revegetation of emersed areas 

 laid bare by receding waters. It is fairly evident that occur- 

 rences of this kind have taken place in the great basins of 

 Nevada and Utah, in the Oteri and other depressions in New 

 Mexico and Arizona, in the Pattie basin in Mexico, and in the 

 Cahuilla basin in southern California. In some the alternations 

 date far back in geologic time and many thousands of years 

 must have elapsed since the last change occurred. In others, 

 such as the Pattie and Cahuilla basins, the transformations fol- 

 low each other rapidly, and although they may have begun far 

 back in time, yet they continue up to the present. 



The Cahuilla Basin lies in the most arid part of North 

 America, and although the making of the lake in the Salton 

 Sink, or portion of the basin below sea-level, may be finally due 

 to climatic factors, yet it is caused directly by overflow from 

 the channel of the Colorado River. The geological record 

 seems to indicate that the sink has been filled and dried out at 

 intervals over a long period extending up to the present time. 



* * The present article was prepared from Publication 193, Carnegie Insti- 

 tution of Washington, 1914, in compliance with the request of the editor of 

 this Journal. No attempt has been made to assign paragraphs, which have 

 been cited intact, to the collaborators in the volume, or to indicate the por- 

 tions that have been abstracted. The reader is referred to the original 

 treatises for details. The data obtained by the eighth annual analysis of the 

 water of the lake in 1914 have been added to the table on page 241, and 

 some other matter not included in the volume has been given. 



Am. Jour. Sci. — Fourth Series, Vol. XXXIX, No. 231. — March, 1915. 

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