170 (icoiixjij uf Hichiiwiul ('ou)ify. X. Y. 



the deposition of the sandstone upon tlieni. and the latter 

 rock subsecpientlj removed by erosion, to tind the intervening 

 space between Kew Jersey and Connecticut cut by trap-dykes, 

 while in fact none have yet lieen observed.* 



C'KETACEOLS FORMATION. 



The Cretaceous formation, more or less covered by glacial 

 and modified drift and salt meadows, extends through all parts 

 of the county lying east and southeast of ihe Archaean rocks. 

 The area underlaid by it is therefore about 28.5 square miles. 



The strata consist of beds of variously colored clays and 

 sands, dipping slightly to the southeast, and having a general 

 strike of about S. 45° W. They are a direct continuation of 

 the "Plastic Clay" division of the Cretaceous, so named by the 

 J^ew Jersey geologists, and. lie at the base of the formation in 

 eastern Nortli America. 



South of the terminal glacial moraine, the strata are generally 

 covered by a dei)osit of grayish-yellow sand and gravel of vari- 

 able tliick)iess, which is known as the Yellow Drift; this is 

 only , seen on Staten Island, in the vicinity of Tottenville, for 

 the area southeast of the moraine near New Dorp and Garretson's 

 is covered with modified drift, imperfectly stratilied. 



These Cretaceous strata of clay and sand, in all probability 

 extend eastward from Richmond. County on to Long Island, 

 and perhaps underlie the latter throughout nearly its entire ex- 

 tent. The clays are white, yellow, brown or black ; they appear 

 on the surface at a number of places, and the ])urer varieties have 

 been extensively used n\ the manufacture of lire-brick, drain- 

 pipe, gas-retorts, and other refractory ware. 



White clays outcrop on the road just north of Hossville, at 

 various places south of "Rossville and near Kreischerville, along 

 a stream near Prince's Bay; they have been noticed near Gif- 

 ford's, and are said to occur at the bottom of a well near New 

 Dorp. They will probably be found at other places. 



* For a full discussion of this "Triassic Arch" question, see I. C. Russell, 

 in Annals of this Academy, Vol. I, 1878, p. 330, and Vol.. II, p. 37, 1880. 



