Influence of Organic Matter Content on Engineering Properties of Clays

Table 2

Chemical composition of peat soil, illite, and quartz sand.

Name	Peat soil	Illite	Quartz sand
SiO2	40.25	78.00	>98.00
Al2O3	21.37	12.33	1.00
TiO2	7.41	1.20
K2O	1.55	7.80
Na2O	2.48
MgO	1.78
MnO	1.53
Others	0.21