SOURCE OF AQUEOUS SOLUTIONS. 1069 



Summarizing, the conclusion is reached that so far as the main work 

 of aqueous ore deposition is concerned the water is that of meteoric origin, 

 which makes its way from the surface into the ground, there performs its 

 work, and issues to the surface again. The amount of water coming from 

 the deep-seated zone of rock flowage, emanating from crystallizing lava 

 and contributed by dehydration, is believed to be relatively small upon 

 the average, although exceptionally important in proportion to its mass. 

 It is held that, at any given time, the meteoric water entering the crust 

 substantially balances that issuing from it, although there may be a slight 

 continuous surplus in favor of the latter. 



My second main conclusion concerning ores deposited by aqueous solutions 

 is that the major part of the water performing the work is meteoric. 



II. SOURCE OF METALS FOR ORES DEPOSITED FROM AQUEOUS SOLUTIOXS. 



It is believed that the greater part of the metals for ores deposited by 

 water is derived from the zone of fracture. If the reasoning thus far 

 be correct, viz, that ores deposited from aqueous solutions are trans- 

 ported to their present positions by underground waters, that in order to 

 transport this material an abundant circulation is required, and that in the 

 deep-seated zone of anamorphism the circulation is a minimum, it follows 

 that the waters derive their metals from the rocks of the zone of fracture. 

 If any one asserts that the metalliferous materials of mineral veins are 

 derived by water circulation from the centrosphere, or are derived from the 

 lithosphere below the zone of rock fracture, I hold this to be a pure 

 unverified assumption, for which there has not as yet been adduced one 

 particle of evidence, and opposed to which stand well-known principles 

 of physics concerning the movement of water in minute openings, and the 

 condition of water in the deep-seated zone. 



The conclusion that the waters derive their metals from the zone of 

 fracture was reached as outlined on the foregoing pages, but since the pub- 

 lication of this conclusion the observational work of Lindgren upon metaso- 

 matic processes in fissure veins has fully confirmed it. Lingdren has made 

 a careful study of the metasomatic changes in the wall rocks while ores 

 and gangues are being deposited. He finds that the abundant minerals 

 produced by metasomatic processes are quartz, fluorite, calcite, magnesite, 

 dolomite, siderite, muscovite, chlorite, kaolinite, zeolites, and the sulphides. 



