68o 



ROLLIN T. CHAMBERLIN 



A specific case of this kind of uncertainty is illustrated by Fig. 5. 

 As a result of much digging for fossils at this point, the bank had 

 gradually been cut back till, at the taking of this picture, it was 

 perhaps 15 feet back from its original canal face. The entire thick- 

 ness of the deposit from the base of the black muck and sand fill 



■&*z*^-?^: 



Fig. 5. — Section of south bank of the canal near point marked N (Fig. 4) as 

 exposed by the party on March 21, 191 7. At the base are buff marine sands with 

 some shells (formation No. 1) ; No. 2 above is the lower creek fill which was originally 

 supposed to extend up to the prominent line of white sand lenses, just beneath 

 marker 3 in the middle of the picture ; but upon more critical inspection, the patches 

 of fill marked 3a and 36 were excluded from the lower fill and placed in the upper 

 fill. No. 3 represents the unmistakable upper creek fill. It contains some small 

 lenses and pockets of marine shells derived from formation No. 1. 



(just to the left of the hammer) to the surface as it was in 1913, just 

 prior to the excavation of the canal, is 5^ feet. As the party viewed 

 the newly exposed section for the first time, all were ready to carry 

 the upper creek filling down to the prominent line of whitish sands 

 and reworked coquina shells just beneath marker 3 in Fig. 5. After 

 a brief inspection, there seemed to be reasons for assigning the block 



