SIM(MFI('ATIOX. 137 



tions referred to. It would b^ eas}-, but Iiardly profitable, to speculate 

 further on this subject, to which I hope to contribute by experiment on a 

 future occasion. 



The basic solutions rising from the granite converted the acid sand- 

 stones into more basic compounds: feldspars, ferromagnesian bisilicates, 

 serpentine, etc. The solutions thus became more acid, and it can hardly be 

 doubted that after producing their full effect upon the setlimentary rocks 

 the waters contained free silica in solution. It is an interesting and impor- 

 tant question what became of this silica, which was certainly in part ex- 

 tracted from the sandstones. It is absolutely certain from the pi'inciple of 

 maximum dissipativity that any solution will deposit its contents or change 

 its chemical character at the very first opportunity or at the first moment 

 when heat can be set free by any chemical or physical alteration. Hence, 

 in general, mineral solutions permeating rock masses can only in very ex- 

 treme cases traverse long distances without substantial change. The silica 

 dissolved by the waters which effected the metamorphism of the rocks of 

 the Coast Ranges must consequently have redeposited this material as near 

 the place where it was dissolved as possible. There appear to be only two 

 possibilities in the case: either the silicification which is so prominent in 

 the Coast Ranges was due to these siliceous waters or the solutions pene- 

 trated to the surface of the region as it then existed and there precipitated 

 so much of their load as could be thrown down under diminished tempera- 

 ture and pressure. My own preconceptions would incline me to the former 

 of these hypotheses, which involves a speedy precipitation and makes a 

 portion of the process of metamorphism independent of material derived 

 from extraneous sources. This may be the true theory, but I have not 

 been able to gather any information confirmatory of it. Throughout the 

 field work efforts have been made to determine the relative age of the proc- 

 esses of metamorphism, and in each area it has appeared that silicification 

 was probably a later phenomenon than serpentiniz'ation, which, again, cer- 

 tainly followed the recrystallization of the sedimentary rocks. Thus ser- 

 pentinoid rocks are often intersected by quartz veins, while such veins 

 partially converted into serpentine or showing infiltrated serpentine have 

 nowhere been detected. Massive serpentines, it is true, are seldom pene- 



