30 Quaternary Formations of Southern New Jersey. 



however, as about Avis Mills, the base is a little lower. The 

 maximum> thickness of the formation here is 40 feet, or possibly 

 a little more. 



Exposures. — There are good exposures of the Bridgeton for- 

 mation between Salem Creek and Oldmans Creek. One is at a 

 gravel pit three-fourths of a mile north of west of Pitts Grove 

 (Pole Tavern), where 7 or 8 feet of gravel carrying cobbles and 

 occasional bowlders may be seen. The formation here rests 

 on the glass-sand phase of the Cohansey formation. The gravel 

 is compact, and is distinctly stratified in rather regular horizontal 

 beds. Bits of crystalline rock are common, though no red shale 

 was seen. A mile northwest of Whig Lane is another good ex- 

 posure showing 6 or 7 feet of compact gravel with only sand 

 enough to fill the interstices between the pebbles. Another pit 

 i~y 2 miles northwest of Whig Lane, on the cross road to Avis 

 Mills, shows gravel finer than that at the pits mentioned above. 

 The gravel here has a strong resemblance to that of the Beacon 

 Hill formation. A mile east of Point Airy is another pit (Fig. 

 17) showing 7 feet of gravel with occasional bowlders of brown 

 standstone or quartzite. The constituents characteristic of the 

 Bridgeton, that is the crystalline rock and the red shale, are 

 present. 



BETWEEN OEDMANS CREEK AND RACCOON CREEK. 



Distribution. — The general relations of the Bridgeton in this 

 area are shown in Fig. 18. The large area of Bridgeton to the 

 southeast (about Hardingville in the section) is continued west- 

 ward between the creeks to Fairview and Lincoln. West of 

 that place, the continuity of the formation is interrupted by 

 valleys. Considerable outliers occur north of Harrisonville, and 

 smaller ones south and southwest of Swedesboro, the one far- 

 thest west being on Scull Hill. 



The altitude of the Bridgeton surface about Fairview is 140 

 to 150 feet, and the top of Scull Hill is 146 feet. The remnants 

 between these places are on hills of similar altitudes. Here there- 

 fore the base of the formation does not decline toward the Dela- 

 ware. 



