CLAYS, SOILS, ETC. 231 
OCEANIC CLAYS. 
e 
Composite analyses of sediments collected by various exploring expeditions. Ma- 
terial contributed by Sir John Murray. The larger number of samples were collected 
by the Challenger expedition. 
A. The red clay. Composite of 51 samples, dredged from the sea bottom in all 
the great oceans. 
B. The portion of A soluble in water. Analyses by G. Steiger, record No. 2300. 
Additional determinations by Hillebrand revealed the presence in the clay of traces 
of molybdenum, and E. ©. Sullivan also found the following percentages of heavy 
metals: CuO, 0.02; PbO, 0.007; ZnO, 0.004; As,O;, 0.0007. 
C. Terrigenous clays, dredged at depths from 140 to 2,120 fathoms. Composite of 
52 samples. 
D. The portion of C soluble in water. Analyses by Steiger, No. 2323. Analyses 
B, D, represent merely adherent sea salts. 
ae om ee 6; D 
ano 
23. 
FeO, 14 
FeO.. 
MgO. 18 
Ca0.. -38 
Na20. 2.12 
Ky 3 : 
HO 8b OD vse na arta escrneteninauemwanenucccamsmvetenccdbteke tec saas 3.28 |.-.....- 4.73 
