1904.] HATCHER MARINE AND NON-MARINE FORMATIONS. 



345 



its, c. to d. the shallow water and littoral deposits extending east- 

 ward from the coast, d. to a.' true marine conditions. 



Let us suppose present conditions to continue without any eleva- 

 tion or depression of the earth's surface jn this region, until by the 

 process of erosion and deposition the present coast line is advanced 

 to a position approximating that of the eastern limits of the conti- 

 nental plateau, as shown in the curved line a. '-a." We would 

 then have deposited between the lines a.-a.' and a.'-a." sediments 

 aggregating in vertical thickness something more than 3000 feet, 

 and comprising four formations more or less distinct when consid- 

 ered from their faunal and lithological characters but of the same 

 age, all four having been laid down in the same time interval 

 and all conformable with one another save for an unconformity by 



Fig. I. 



overlap along their western borders necessitated by the topography 

 existing at the time when present conditions were inaugurated. 

 Commencing below. No i. of these four formations would be the 

 thickest of the series and would form a wedge of purely marine and 

 deep water deposits at the base with the blade directed westward. 

 Above these deep water deposits would come No. 2 of the series, a 

 marine shallow water and littoral deposit of nearly uniform thick- 

 ness, which would be determined by the depth of water at which 

 such deposits may take place. This would contain a littoral fauna 

 and would overlap the western border of No. i. Above this and 

 overlapping it on the west would come No. 3, an estuary formation 

 with its beds of oysters and other brackish water mollusca, now 

 occurring in such abundance in the sounds and bays of this coast. 

 The vertical range of these brackish water deposits, like that of No. 



