210 SMITH— PARAGENESIS OF MINERALS. [Octobers, 



the rocks of Mt. Diablo; Nutter and Barber^ observed the same 

 thing in the metamorphic rocks near Healdsburg. 



The garnetiferous glaucophane schists resemble very closely 

 those of Syra in the Grecian Archipelago, described by Liidecke.^ 

 The minerals that compose it, and the rocks with which they are 

 associated are the same in both. But one analysis of the garnet- 

 glaucophane schist of California has been published, that given by 

 H. W. Turner^ of a schist from Pine Canon, Mt. Diablo. This 

 analysis is quoted below, along with another of a similar schist from 

 Tupper Rock, near Brandon, Oregon, published by H. S. Wash- 

 ington. ^ 



Analyses of Garnet Glaucophane Schists. 



^ I. II. 



SiOs 47.84 4915 



AI2O3 16.88 15.87 



Fe-Os 4.99 " 4-10 



FeO 5.56 7.58 



MgO 789 ' 7-53 



CaO ■ II. 15 9.06 



NasO 3-20 3.59 



K2O 0.46 0.54 



H2O (above 105° C.) 1.81 (above 110° C.) 1.07 



H2O (below 105° C.) 0.17 (below 110° C.) 0.16 



Ti02 1. 19 



MnO 056 trace 



P2O5 0.14 



Total 100.65 99.84 



I, Garnet-glaucophane schist, Pine Canon, Mt. Diablo, California, Melville, 

 analyst; H. W. Turner, Bull. Geol. Soc. Amcr., Vol. II., 1891, p. 418. 



II. Garnet-glaucophane schist, Tupper Rock, near Brandon, Oregon, H. S. 

 Washington, analyst; A Chemical Study of the Glaucophane Schists, Amer. 

 Jour. Sci., IV. Ser., Vol. XL, 1901, p. 53. 



A comparison of these analyses with those of Ransome's fourchite 

 and Becker's pseudodiabase, shows the agreement to be perfect, and 

 it can not be doubted that they were all originally the same thing. 



1" On Some Glaucophane and Associated Schists in the Coast Ranges of 

 California," Jour. Geol., Vol. X. (1902), p. 74i- 



2" Der Glaucophan und die Glaucophan fiihrenden Gesteine der Insel 

 Syra," Zeit Deutsch. Geol. Gesell, Bd. XXVIII. (1876). 



3" The Geology of Mt. Diablo, etc.," Bull. Geol. Soc. Amer., Vol. II., p. 418. 



*" A Chemical Study of the Glaucophane Schists," Amer. Jour. Sci, 4th 

 Ser., Vol. XI. (1901), p. 53- 



