44 Washington — Study of the Glaucophane Schists. 



One is a gray- green schist from the neighborhood of a 

 large serpentine dike, at La Barclietta, near Bastia, of which, 

 not having access to the original paper by Oels,"" I can give 

 no description. It is, however, possibly the same as that 

 described by Oebekkef from the same locality, as com- 

 posed of prismatic glaucophane, partly altered to chlorite, 

 granular epidote, plagioclase, quartz and calcite. 



The analysis (No. I, below) shows low Si0 2 and CaO, with 

 very high alkalies, and Fe 2 3 largely preponderating over 

 FeO. It does not correspond with the description given by 

 Oebekke, nor, in fact, as far as the iron oxides and alkalies are 

 concerned, with any other analysis of a glaucophane schist. 



The other is a glaucophane schist from the gneiss of Bastia, J 

 a dark, tine-grained, tough rock, composed of " orthoclase, some 

 oligoclase, needles and prisms of glaucophane, sahlite, iron mica 

 and chlorite, with other secondary products." 



The analysis, given in II below, is unsatisfactory, and of 

 little value, as FeO, alkalies and H 2 have not been deter- 

 mined. As far as it goes it is rather anomalous for a glauco- 

 phane schist, and resembles most that of the rock from Cafe 

 Skarbeli, in Syra. 



I. II. 



Si0 2 50-17 55-94 



A1 2 G 3 13-88 18-06 



Fe 2 3 .. V80) 



FeO 1-69 f 12 17 



M^O 4-53 2-75 



CaO 10-90 5-95 



Na„0 _.. 7*31) K ,„ ,-,.«: n 



K 2 6 2-16 f 5 ' 13 ( dlfference ) 



H 2 2 1-56 not. det. 



MnO 0-59 



100-59 100-00 



I. Glaucophane schist. La Barchetta. Bastia. Corsica. M_ 

 Oels anal. Ref. in Neu. Jahrb. ]896, i, p. 47. 

 II. Glaucophane schist, near Bastia, Corsica. Busatti anal. Ref. 

 in Neu. Jahrb., 1897, i, p. 281. 



Japan. 

 Glaucophane schists are of quite common occurrence among 

 the metamorphic rocks of Japan, § and a number of them have 

 been described by Koto. From him I received several speci- 

 mens of typical material, two of which were analyzed. 



*M. Oels, Inang. Diss. Erlangen. 189J, Ref. in Neues Jahrb. 1896, I, p. 47. 



\ Oebekke, Zeitschr. d. deutsch. geol. Ges., vol. xxxviii, p. 647, 1886. 



\ Busatti, Atti Soc. Tosc. Sci. Nat., Mem. xiii, p. 1-19, 1894: Ref. in Neues 

 Jahrb. 1897, i, p. 281. 



§Koto, Jour, of Sci. College, vol. i, Pt. i, p. 85, 1886. Harada, Die Japanischen 

 Inseln, Berlin, 1890, pp.' 54, 62. 



