282 University of California Publications in Geology [Vol. 13 



In the year 1893 Franz Posepny expressed his idea that the bulk 

 of mineral-bearing - waters are essentially meteoric. He said : 7 ' ' There 

 is a descent of groundwater through the capillaries of the rock, even 

 in the profound region. Having arrived at a certain depth it is prob- 

 able that a lateral movement takes place toward the open channels. 

 Having reached these it returns, ascending to the surface." In this 

 opinion C. R. Van Hise concurred. He denned capillary sheets as 

 having widths varying from 0.204 mm. to 0.0001 mm., and indicated 

 his belief that heat, pressure, and time must tend to increase the 

 mobility and flow of water in the deep regions, as against the counter 

 effects of friction and discontinuity. He says : 



We conclude from the foregoing, that while underground circulation of water 

 upward, downward, and lateral, is a possibility within the zone of rock flowage, 

 it is very slow, and that it can not be appealed to to explain metalliferous de- 

 posits.s However, the ores are directly derived from rocks in the zone of fracture 

 by circulating underground waters. The rocks which furnish the metallic com- 

 pounds may be intituled igneous rocks; they may be extruded igneous rocks; 

 they may be original rocks of the earth 's crust ; they may be sedimentary rocks ; 

 they may be the altered equivalents of any of these. .... Hence so far as the 

 main work of ore deposition is concerned, the water is that of the zone of rock 

 fracture, and this water is water of meteoric origin, which makes its way from 

 the surface into the ground, and there performs its work and issues to the surface 

 again. 



T. A. Riekard also concurred; 10 and A. C. Lawson treating the 

 subject at greater length said : X1 



The circulation of the ground-water would in every case be profoundly dis- 

 turDed by the injection of hot igneous magmas into sedimentary terranes. The 

 disturbance would, however, be far from chaotic. The presence of the hot body 

 would be the controlling influence in determining the circulation. The circula- 

 tion would always be upward on the periphery of the hot mass. This would be 

 true not only while it was still molten, but also long after it had solidified. Such 

 a circulation of the heated ground-water would be quite competent to do all 

 that is ascribed to magmatic water, including the formation of lime-silicate zones. 

 It would not only bring to a zone of active chemical reaction the materials leached 

 from the surrounding region, but it would attack the still hot, though solid, 



igneous mass itself and abstract from it part of its metallic constituents 



I will first, however, disclaim the belief, which I fear will be imputed to me if 

 I do not anticipate the imputation, that the sedimentary rocks of the earth's crust 

 everywhere contain similarly large quantities of water The inequality of 



7 The genesis of ore deposits, p. 38; also A. I. M. E. Trans., vol. 23, p. 197, 

 1893. 



8 Some principles controlling the deposition of ores, A. I. M. E. Trans., vol. 30, 

 p. 45. 



9 Op. cit., p. 46. 



10 Eng. and Min. Jour., Feb., 1894. 



11 Ore deposition in and near intrusive rocks by meteoric waters, Univ. Calif. 

 Publ., Bull. Dept. Geol., vol. 8, p. 221, 1914. 



