GEOLOGY OF SARATOGA SPRINGS AND VICINITY I29 



The water is no doubt present as a constituent of the glass. The 

 interest attaching to the presence of carbon more than compensates 

 for the sHght uncertainty introduced into the analysis. 



Si02 



47-55 



A1203 



16.65 



FeaOs 



4.94 



FeO 



5.12 



MgO 



5.63 



CaO 



4-77 



Na^O 



4.20 



K2O 



2.52 



H2O+ 



5-57 



H.O— 



0.24 



TiOa 



0.87 



P2O5 



0.27 



CI 



O.IO 



F 



0.06 



S 



0.0 1 



MnO 



0.46 



C 



0.80 



CaCOs 



0.34 



Total 100.10 



Selected rock from the center of one of the large lava balls, as free as 

 possible from calcite. E. W. Morley, analyst. 



The calculated norm of the rock would be 



Orthoclase 



15.01 



Olivine 



12.64 



Albite 



33.01 



Magnetite 



7.19 



Anorthite 



18.90 



Ilmenite 



1.67 



Nepheline 



1.42 



Apatite 



0.67 



Diopside 



2.48 







Totalling 92.99 per cent ; the residue consisting of water, carbon 

 and calcium carbonate. The rock classifies in 



Class 2, Dosalane Rang 3, Andase 



Order 5, Germanare Subrang 4, Andose. 



It is thus a member of a very large rock group, of diabasic or 

 basaltic composition. It is quite near some of the Newark traps, 

 that from Medford, Mass., analyzed by Merrill for example, though 

 it is a more basic rock than the average Newark traps, which run 

 from 52 to 53 per cent of silica. 



