CHAPTER H. 



THE RARITAN CLAY.' 



The Raritan 2 formation is the lowest division of the Cre- 

 taceous in New Jersey. It consists of a number of beds of clay, 

 sand, and locally gravel. The clays are of various sorts, from 

 nearly white to steel-blue and black, some beds are often sandy 

 and at times considerable quantities of pyrite and lignite are 

 included. Some of the sands are nearly pure quartz, sharp and 

 angular in grain, others are highly micaceous, or lignitic or 

 arkose. 



In the report on the Clays and Clay Industry of New Jersey 3 

 seven beds are described which may be included in the Raritan 

 formation proper : these beds being ( i ) "Raritan Fire and Terra- 

 cotta (Potter's) clay," (2) "Fire Sand No. i," (3) "The Wood- 

 bridge Clay," (4) "The Feldspar-Kaolin Sand Bed," (5) "South 

 Amboy Fire Clay," (6) "Sand Bed No. 3," (7) "Amboy Stone- 

 ware Clay. The total thickness of these beds is in the neighbor- 

 hood of 200 feet. These subdivisions are, however, strictly local, 

 and applicable only to the northeastern section in Middlesex and 

 MonmO'Uth counties. 



Flora and Fauna of the Raritan Series, By far the most 

 abundant fossil remains in the Raritan series are plants, and in 

 a monograph upon the flora of the Amboy clays, Newberry 4 has 

 described 156 species, most of which are from the Raritan forma- 



1 The descriptions of the physical characters of the formations have been 

 compiled largely from the discussion of the formations by Kummel and 

 Knapp in Volume VI of the Final Reports of the State Geologist upon the 

 Clays and Clay Industries of the State, and from the descriptions by Clark 

 and Cook, supplementing the field observations of the writer. 



2 The term is here used in a restricted sense, indicated on page 22. 



3 Geol. Surv. N. J., Final Rep., vol. vi, pp. 168-196. 



4 The Flora of the Amboy Clays, by J. S. Newberry, a posthumous work 

 edited by A. Hollick, Monog. U. S. G. S., vol. 26 (1895). 



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