6 AKT. 1-2. — E. KOTÔ : 



a) Slaty inica=schist (PL I. fîg. 2.) 



Composition : Essential: Quartz, albite, sericite. 



Accessory: Rutile, hematite, magnetite, 

 graphitoicl, biotitc, tourmaline, hematite. 

 Macrotexture: Thin crystallization-schistose ^\ even, cleav- 

 age plane fine- wrinkled. 

 Microtexture : Homeoblastic, granoblastic, Icpidoblastic. 

 The schist is an aluminosilicate rock of a light-gray color, weather- 

 ing a rusty brown, its fresh schistose plane being a glistening white 

 with a silky lustre. It is the true TliOwjUmm er schiefer of the Ger- 

 mans, The ground is composed of iuterdigitate grains of quartz and 

 albite (?) with concertai (mosaic) fabric. I have not succeeded in 

 distinguishing the two kinds of grains by the staining method. On 

 the ground, the confused, tattered lamellœ of sericite are arranged in 

 thin laminae. The sericite is full of black dust which is only partially 

 dissolved away by HCl, while the rest disappears only after ignition, 

 thus betraying the presence of both magnetite and graphitoid. Tlie 

 sericite also houses superabundant needles of rutile, which are a little 

 larger in size than those of Sauee's clayslate-needles (see fig. 2.). A 

 few knee-shaped twins of rutile are also observed. 



The rutile-ueedles together with the above-mentioned dusts make 

 the reck, even in thin slices, appear like a graphite-schist. Hemimor- 

 phic tourmaline is also found, showing that the rock is a contact- 

 metamorpliosed one. Brownish hematite and biotite complete the list 

 of components. Locality : Kullui-Jwgai '\ nortli of Sang-u'on "^K 



b) Chlorite=Muscovite=schist. 



Composition: Essential: Quartz, clinochlore, muscovite. 

 Accessory: Magnetite, tourmaline, rutile, 



1) Tlie nomenclature used in the followiug pages is that inaugurated by Professors F. 

 Becke and Gkucenmann, Gkubenmann : " Die Krystallinen Schiefer." Berlin, 1904-1907. 



2) mm% 3) #M 



