240 SMITH— PARAGENESIS OF MINERALS. [Octobers, 



Nos. XIL, XV., XVI., XVII. and XIX. are basic glaucophane 

 schists, but the chemical analyses show them to have been gabbros 

 or diabases. 



No. XVIII. is a massive eclogite, composed of garnet, omphacite 

 actinolite, glaucophane, white mica and titanite, but the chemical 

 analysis shows it to have been a basic gabbro or even possibly a 

 pyroxenite. No rocks of the chemical nature of peridotite have 

 been discovered by chemical analysis among the glaucophane schists, 

 but some of the actinolite chlorite schists would probably show such 

 a constitution. 



These results all show that there is no need of supposing that 

 magnesian or alkaline or siliceous solutions have permeated the 

 altered rocks, adding one substance and taking away another. The 

 small amounts of mechanically contained water in all the sediments, 

 and the water disseminated through all the cracks in the igneous 

 rocks have been sufficient, when heated under pressure, to produce 

 all the phenomena of recrystallization seen in the Coast Ranges. 

 This small amount of water would not have been sufficient to produce 

 aqueo-igneous fusion, nor is it likely that this condition was ever 

 reached, for the minerals were not all crystallized at the same time. 

 But each molecule of water, with almost unlimited time, could 

 accomplish a great deal of work, and this work was not finished until 

 that molecule was fixed as water of constitution in some mineral. 



BIBLIOGRAPHY. 



Barber, W. B. (E. H. Nutter and ). 



1902. On some glaucophane and associated schists in the Coast Ranges of 

 California. Jour. Geol, Vol. X., 1902, pp. 738-744. 



Becker, G. F. 



1888. Geology of the Quicksilver deposits of the Pacific Slope. Monographs 

 of the U. S. Geol. Survey, Vol. XIII. 



Blasdale, W. C. 



1901. Contributions to the mineralogy of California, Bulletin of the Dept. 



Geol. University of California, Vol. II., pp. 327-348. 

 Clark, W. 0. (Unpublished paper.) 

 Diller, J. S. 

 1896. A geological reconnoissaince in northwestern Oregon, 17th An. Rept. 



U. S. Geol. Survey, pp. 447-520. 



