THE RADIOACTIVITY OF THE WATERS OF THE MOUNTAINOUS 

 REGION OF NORTHERN LUZON ' 



By George W. Heise 



{From the Laboratory of General, Inorganic, and Physical Chemistry, 

 Bureau of Science, Manila) 



ONE PLATE AND TWO TEXT FIGURES 



In a previous paper 2 the results of a series of measurements 

 of the radioactivity of typical Philippine waters were reported. 

 About 90 waters were examined, including 44 from springs in 

 the mountainous region of northern Luzon. This province is, 

 in the main, a volcanic region, of which the — 



Geology clearly indicates, geologically speaking, the evidence of only 

 recent vulcanism.* 



It contains an abundance and a variety of springs, many of 

 them hot and heavily mineralized; hence it is an especially 

 desirable place for work of this kind. 



In the work referred to, there was no apparent relation to 

 be deduced between the radioactivity of the waters and the 

 chemical quality of the geological formations from which they 

 were derived. The work done was admittedly preliminary in 

 character, and the result could not be considered conclusive. 



With the exception of certain sources in Ifugao subprovince, 

 the springs examined in Mountain Province were uniformly low 

 in radium emanation content. There was no apparent reason 

 for this peculiarity, as the waters studied were from many 

 different geological formations and showed great variation in 

 chemical quality. 



It seemed of possible significance that the only strongly radio- 

 active waters were encountered in Kiangan and Banaue, the 

 only places east of Polis Range at which we had made examina- 

 tions. However, the available time and the exigencies of moun- 

 tain travel did not permit more extensive investigation. Re- 

 cently it has been found possible to extend the work, with the 

 results set forth in this paper. 



In addition to the places mentioned in the preceding report, 

 the accompanying map (fig. 1) shows the following places at 



1 Received for publication July, 1917. 



2 Wright, J. R., and Heise, G. W., The radioactivity of Philippine waters, 

 This Journal, Sec. A (1917), 12, 145. 



' Eveland, A. J., Notes on the geology and geography of the Baguio 

 mineral district, ibid. (1907), 2, 207-233. 



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