CHAPTER IX. 



ON THE THERMAL EFFECT OF THE ACTION OF AQUEOUS 

 VAPOR ON FELDSPATHIC ROCKS. 



BY CARL BARUS. 



Mr. Church,' in his report on the geology of the Comstock Lol>e, has en- 

 deavored to account for the abnormally rapid increase of the temperature 

 of this District with increasing depth^ by ascribing it to chemical action — 

 more immediately to the decomposition (kaolinization) of the feldspathic 

 rocks in consequence of the presence of moisture. This theory, however, 

 notwithstanding the ingenuity with which it has been discussed by its 

 author, is based on an assumption that has scarcely a single experimental 

 datum to support it; nor is the fundamental hypothesis upon which Mr. 

 Church bases his argument, namely, that the process of kaolinization is one 

 from which we may, a priori, expect the production of heat (as Mr. Becker 

 has already pointed out) by any means of a kind to be readily admitted. 



General plan. — It appeared vcry desirable, therefore, insomuch as from 

 theoretical grounds alone there is abundant room for difference of opinion, 

 to put the matter to a direct physical test. At the outstart, and with the 

 time and means available in camp, qualitative experimentation only could 

 judiciously be attempted, the necessarily complicated quantitative study 

 being reserved for more favorable opportunities; if, indeed, the preliminary 

 investigation should furnish i-esults of sufficient interest to warrant further 

 research. 



The thermal effect of kaolinization (abbreviated T. E. K.) may be de- 

 fined as the quantity of heat produced by the action of aqueous vapor on 



' The Comstock Lode, its formation and history, by John A. Church, 1879. 

 -This volume, Chapter VII. 

 •i90 



