Bfack River 
29 
Figure 4. Comparative section of the Black River and Trenton strata. 
(Figures in brackets refer to detailed sections on pages 
30 to 39.) 
Note. The apparent increase in thickness of the Black 
River beds at MacLaren landing is due probably to slight 
faulting under the covered area. Between the exposures “7,” 
and “6” is a very long field, and the similarity of the fossil 
content also points to the probability of a duplication of a 
portion of the beds. 
