VIEWS SHOWING CHARACTERISTICS OF THE LAND 
PEBBLE PHOSPHATE DEPOSITS AND OF THE 
PHOSPHATIC MARLS WHICH LIE BENEATH. 
Fig. 20.—Phosphatic marl. The sample here illustrated was taken from 
Black Creek. A similar marl, however, lies beneath the land pebble phosphate 
deposits and is known as the “bed rock.” 
The analysis of the phosphate pebbles washed from this sample is as follows: 
Moisture - .88 
Insoluble matter, sand, etc.- 18.94 
Phosphoric acid, 24.45, equivalent to tricalcium phosphate —-— 5340 
Iron and alumina - 0.23 
Calcium oxide, 5.07, equivalent to calcium carbonate-- 11.53 
Fig. 21.—Sample from the land pebble phosphate bed showing light colored 
phosphate pebbles imbedded in the matrix. From the pit of the Prairie Pebble 
Phosphate Company near Mulberry. 
The following is an analysis of this sample of matrix: 
Moisture - .78 
Insoluble matter, sand, etc.- 25.18 
Phosphoric acid, 26.73, equivalent to tricalcium phosphate- 58.38 
Iron and alumina- 7.51 
Calcium oxide, 1.02, equivalent to calcium carbonate- 2.32 
The following is an analysis of phosphate pebbles washed from this matrix: 
Moisture - 1.33 
Insoluble matter, sand, etc.-- 6.87 
Phosphoric acid 35.34, equivalent to tricalcium phosphate- 77.18 
Iron and alumina- 0.93 
Calcium oxide, 1.39, equivalent to calcium carbonate- 3.16 
92 
