40 Washington — Study of the Glaucophane Schists. 



rather coarse-grained specimen of quartz-mica-glaucophane 

 schist, with a few accessory garnets. It just sank in a solution 

 of sp. gr. 3*11, and was examined with the microscope and 

 seen to be extremely pure. 



My analysis (the mean of two) is shown in I, and for 

 comparison are given the analyses of Lnedecke (II) and 

 Schnedermann (III), taken from the paper of Luedecke (p. 

 252), already cited. It is hoped to discuss this analysis, along 

 with other new ones, in a subsequent paper. 



I. ii. in. 



Si0 2 57-67 55-64 56'49 



A1 2 3 11-07 1511 12-23 



Fe a 3 3-20 3-08 



FeO 9*68 6'85 10-91. 



MnO 0-06 0-56 0'50 



MgO 9-85 7*80 7-97 



CaO 0-95 2-40 2*25 



Na a O 6-80 • 9-34 9'28 



K 2 G 042 .... 



H 3 OllO° + 0-36 



H 2 110° — 0-12 



100*18 100-78 99*33 

 Attica. 



The investigation of Lepsius* have shown that both the 



gabbros and the Cretaceous shales of Attica have been altered 



to glaucophane schists, through regional metamorphism. 



I. II. 



Si0 2 48-00 45-97 



A1 2 3 15-80 18-18 



Fe 2 3 11-76 5-95 



FeO 3-29 2-30 



MgO 7-70 7-50 



CaO 5-51 8-29 



Na 9 . 3-42 4-10 



K 2 0-46 0-75 



H 2 4-20 6-50 



P 2 5 trace trace 



S trace 



MnO trace trace 



100-14 99-54 



I. Gabbro. Kypriano, near Laurium. Lepsius anal., op. cit., 

 p. 101. 

 II. Gabbro. Malje Kuki, near Daskalio. Lepsius anal., op. cit., 

 p. 102. 



* Lepsius, G-eologie von Attika, Berlin, 1893. 



