ANALYSES OF GASES AT VOLCANIC VENTS 239 



K AT MAI, BY ALLEN AND ZIES 



In the Katmai region of Alaska the enormous development of fuma- 

 roles following the great explosive outbreak of June, 1912, has even sug- 

 gested for one district the appropriate name "The Valley of Ten Thou- 

 sand Smokes." 20 As part of the work of the expeditions supported by 

 the National Geographic Society, samples of the emissions were taken by 

 J. W. Shipley in 1917 and by E. T. Allen and E. G. Zies in 1919. The 

 analyses have been made in the Geophysical Laboratory in Washington, 

 and by the great kindness of Doctors Allen and Zies I am permitted to 

 summarize them in advance of publication. All the percentages are in 

 volumes. Steam is overwhelmingly the most abundant, and in the aver- 

 age of fifteen samples was 99.81 per cent. In the highest sample it is 

 9999; in the lowest, 98.6. The average of the total fixed gases is nat- 

 urally 0.19 per cent, and in the fifteen the highest is also naturally 1.4 

 per cent and the lowest 0.01 per cent. In order of abundance we have in 

 the average, expressed in percentages, carbon dioxide, 0.106 (maximum, 

 0.986; minimum, 0.003); nitrogen and argon, .013 (maximum, 0.268; 

 minimum, 0.002) ; hydrogen sulphide and hydrogen, 0.024 (maximum, 

 0,051 ; minimum, 0.002) ; methane, 0.016 (maximum, 0.169; minimum, 

 0.001) ; oxygen, 0.002 (maximum, 0.083; minimum, 0.001). One deter- 

 mination gave carbon monoxide 0.008. 



In a series of twenty samples, taken in 1917 by J. E. Shipley, dissolved 

 gases were caught in a barium hydroxide train, so as to give the follow- 

 ing volume percentages: hydrochloric acid — average, 0.117 (maximum, 

 0.566; minimum, 0.006); hydrofluoric acid — average, 0.032 (maximum, 

 0.099: minimum, 0.003); hydrogen sulphide — average, 0.029 (maxi- 

 mum, 0.095; minimum, 0.0007). These determinations are of especial 

 interest when used in the interpretation of emissions from intrusives, 

 because they show three of the mineralizers with which we necessarily 

 have a great deal to do. I am, therefore, especially indebted to Messrs. 

 Allen and Zies for the advance records. 



COMPILATIONS BY F. C. LINCOLN 



It is interesting to compare with the results just summarized the 

 earlier information made available in 1907 by F. C. Lincoln, 21 at the 

 time one of my graduate students. Doctor Lincoln compiled all the 

 accessible analyses of volcanic emissions, about two hundred in number. 

 From these he selected fifty, regarded as both typical and reliable. After 

 discussing the probabilities of the admixture of air with the samples and 

 allowing for its influence on the computed averages, Doctor Lincoln 



