RARITAN FORMATION— DESCRIPTION. 



19 



along a subsiding estuary shore line. Comparable deposits are 

 being laid down at the present time in Delaware Bay, Chesapeake 

 Bay, the Gulf of California, and similar more or less land-locked 

 estuarine bodies of water. The preserved fauna, while compara- 

 tively meager, shows fresh or brackish aquatic types with local 

 instances of strictly marine forms which show that the country 

 was low-lying and not much above sea level and subject to occa- 

 sional inroads of the ocean waters. While it is not feasible to 

 map the shifting members of the Raritan formation, it is still 

 possible, especially in Middlesex County, where so many open- 

 ings have been made, to divide the formation into the seven 

 members shown diagrammatically in Figure 2. The basal con- 



Period. Formation. 



Magothy. 



Beds. 



Section. 



Amboy 



stoneware 



clay. 



Sand bed 

 No. 3- 



Raritan. 



Newark. 



South Amboy 

 fire-clay. 



Sand bed 

 No. 2. 



Woodbridge 

 clays. 



Sand bed 

 No. I. 



Raritan pot- 

 ters' and plas 

 tic clays. 



Newark 

 shales. 



New Jersey Plant 

 Localities. 



Cliffwood, Morgan, 

 Kinkora, etc. 



Pensauken Creek 

 (Hylton Pits). 



South Amboy. 



__^__^ Woodbridge, Florida 

 -TL ^ -_ ^ Grove, Sayreville, 



Perth Amboy. 



Milltown. 



Milford, Boonton, 

 etc. 



Pig. 2. — Ideal generalized columnar section of the Raritan and adjacent 

 formations in Middlesex county, showing levels from which fossil plants have 

 been collected. 



