CLAYS IN TERTIARY FORMATIONS. 143 



deep borings. 1 Northeastward towards Ewan Mills the clay 

 apparently thins out. At Haines & Son's brickyard, south of 

 Yorktown, it has a thickness of 50 feet, as determined by boring. 

 Along- Salem creek it is exposed in frequent outcrops from Fox's 

 mill, near Pittsgrove, nearly to Woodstown, a distance of 4 

 miles, in which the entire thickness of 75 or 80 feet is crossed. 

 It is apparently a continuous bed of clay, without sand beds of 

 sufficient extent to show themselves in outcrop. Northeast of 

 Harrisonville, however, it rapidly thins out, giving place to sand, 

 and towards Ewan Mills, a thick bed of sand apparently occupies 

 its middle portion. A mile southwest of Five Points (Rich- 

 wood) and one and one-half miles north of Ewan Mills a clay 

 bed 4 to 6 feet thick apparently corresponds to> the basal portion 

 of the Alloway clay. No further trace of it has been found to 

 the northeast. 



At present this clay bed is being worked only in one locality — 

 Haines & Son's brickyard — south of Yorktown. At Fenwick 

 (169) a secondary surface clay derived largely from this clay 

 bed was formerly utilized in a small way. This clay is avail- 

 able over wide areas, some of them advantageously located, 

 as regards railroad facilities. It is finely developed on the lower 

 slopes of Big Mannington hill, about a mile from the railroad, 

 and also in the railroad cuts at Riddleton Junction and at Allo- 

 way. 



Character. — It is usually a light-brown color, although some 

 portions are white, yellow, or even black. Where weathered, 

 it is traversed by many joints, breaking it up into small pieces, 

 with conchoidal fractures. These joints are locally filled with 

 iron crusts, Plate II, Fig. 2, which diminish greatly its value. 

 The rich farming country underlain by this clay bed is shown in 

 Plate V, Fig. 2. Samples of the clay were taken at many localities 



1 At Glassboro it was penetrated at 90 feet from the surface, at an elevation 

 of 50 feet A. T., where it was 55 feet thick (Ann. Rep. '93, p. 407) ; at Clayton, 

 98 feet from the surface at an elevation of 46 feet A. T. (Ann. Rep. '95, p. 

 89) ; at Williamstown 5 feet of black clay 66 feet below tlie surface between 

 elevations of 84 feet and 79 feet A. T., may, perhaps represent it (Ann. 

 Rep... '97, p. 255) ; 1 mile south of Daretown it apparently occurs 80 feet 

 below the surface from 60 feet A. T. to 35 feet A. T. (Ann. Rep. '97, p. 250). 



