90 Carl Fred. Kolderup. 



The cement of the green sandstones contains essentially chlo- 

 rite, epidote, quartz and some felspar. In the cement of the red 

 sandstones ironoxides play an important role. 



The analyses below show the chemical composition of: I. 

 Green sandstone from the top of Bleien. II. Fine-grained red sand- 

 stone from Eidsfjeld. III. One of the more acid types of the 

 underlying mangerite syenite (for comparison). 



I. II. III. 



S1O2 59,96 57,89 56,46 



Ti02 0,59 0,75 0,45 



AI2O3 16,52 13,39 19,08 



Fe20a 2,37 3,71 2,60 



FeO 3,20 2,50 3,02 



MnO 0,09 0,07 0,18 



MgO 2,47 2,73 0,34 



CaO 5,32 7,56 5,70 



Na*0......... 5,00 3,39 6,09 



K2O. 2,82 2,26 4,22 



P2O5 . 0,24 0,28 0,39 



S 0,00 0,14 0,03 



CO2 spor 0,44 spor 



H2O4-110°C 0,15 0,73 0,18 



H2O + 1 10 ° C. . . . . 1,27 3,81 1,39 



Sum 100,00 99,65 100,13 



As will be seen there is some conformity between I. and III. 



The amount of SiC>2 is relatively low in the sandstones, but 

 the amounts of AI2O3 and MgO high. The felspar must be rather 

 undecomposed as proved by the microscopical investigations. Jn 

 both types of sandstone as well as in the syenite the amount of 

 Na20 is higher than the amount of K2O. The total amount of 

 alcalies in the sandstones is lower than in the analysed variety 

 of syenite, but we also find varieties of syenite where it is lower 

 than in the sandstones. 



The comparison between the two types of sandstones shows 

 that the green sandstone has the highest amounts of SiOa, AI2O3, 

 FeO and Na20, the red the highest amounts of Fe203, CaO, K2O 

 and H2O. The green contains the most undecomposed material. 



