SOIL-POEMING PROCESSES 



33 



Table III 



FRESH GRANITE AND ITS EESIDtrAL CLAY 



Constituents 



EOCK 



Soil 



Percentage 

 Lost' 



SiO, 



60.69 



45.31 



52.45 



AI2O3 



16.89 



26.55 



.00 



Fe,0, 



9.06 



12.18 



14.35 



CaO 



4.44 



.00 



100.00 



MgO 



1.06 



.40 



74.70 



K^O 



4.25 



1.10 



83.52 



Na^O 



2.82 



.22 



95.03 



Pa05 



.25 



.47 



.00 



Ignition 



.62 



13.75 



gain 



Table IV 



VIRGINIA LIMESTONE AND ITS RESIDUAL CLAY « 



Constituents 



Bock 



Soil 



Pebcentage ' 

 Lost 



SiOj 



7.41 



57.57 



27.30 



Al^Oa 



1.91 



20.44 



.00 



Fe^Oa 



.98 



7.93 



24.89 



CaO 



28.29 



.51 



99.83 



MgO 



18.17 



1.21 



99.38 



K.0 



1.08 



4.91 



57.49 



Na^O 



.09 



.23 



76.04 



P2OB 



.03 



.10 



68.78 



CO, 



41.57 



.38 



99.15 



H,0 



.57 



1 6.69 



gain 



^The percentage loss of any constitnent is calculated as follows: 

 A XlOO 



= X 100 — X=% Lost. 



BX 





 D 



A = % any constituent in residual material. 

 B =; % same constituent in fresh rock. 

 C = % of the constant constituent in residual soil 

 D = % of the constant constituent in fresh rock. 

 ^Diller, J. S., Educational Series of BocTc Specimens; U. S. Geol. 

 Survey, BuL 150, p. 385. 1898. 



