THE FLORA OF THE AMBOY CLAYS. 
By J. S. NEwBERRY. 
INTRODUCTION. 
The so-called Amboy Clays take their name from Perth Amboy and 
South Amboy, places in New Jersey which are nearly in the center of an 
area dotted over with clay pits from which are taken potters’ clay, fire clay, 
paper clays, etc. These clays constitute an important item in the mineral 
resources of the State. The formation which includes them is some 350 
feet in thickness and forms the basal member of the Cretaceous group as 
it is developed in the State of New Jersey. The upper member of the 
‘retaceous series consists chiefly of sands and greensand marls, the latter 
being largely used as fertilizers. These sands and marls contain abundant 
marine fossils, many of which have been found in the Cretaceous rocks of 
the Old World, and they have been proved by the investigations of Morton, 
Meek, Whitfield, and others to be the equivalents in geological age of the 
White Chalk of England. 
The Amboy Clays, to which our attention is now more particularly 
directed, outcrop in a belt extending diagonally across the State, forming 
the east bank of the Delaware River for a long distance above and below 
Philadelphia, leaving the Delaware at Trenton and stretching across the 
State at its narrowest point to Raritan Bay, and thence, passing over 
the southern portion of Staten Island, where, as in the State of New 
Jersey, they are largely worked for economic purposes. They are then 
interrupted by The Narrows and New York Harbor, as well as by the 
crystalline rocks which occupy New York Island and underlie the northern 
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