EXPLANATION OF PLATE 4. 
Fig. 1.—View in pit of Pierce Phosphate Company, showing the irregular 
top surface of the bed rock (Arcadia marl) after the removal of the -phosphate 
stratum. Phosphate plant in the background. 
Fig. 2.—View in the pit of the Coronet Phosphate Company, Lakeland, 
Fla. Unconformity between the coarse phosphate above and the finer pebble 
phosphate below. This unconformity, although imperfectly shown in the pho¬ 
tograph, is well marked at this locality. The material above is a coarse con¬ 
glomerate, that beneath is fine pebble imbedded in clay. 
Fig- 3-—View in pit of Standard Phosphate Company, showing irregular 
line of contact, apparent unconformity, between the loose surface sand and the 
more indurated sand beneath. 
