CHAPTER V. 



THE WOODBURY CLAY. 



The Woodbury formation is a black clay, somewhat micaceous, 

 not sandy in the lower portion but slightly so in the upper part 

 where it is at times distinctly laminated. The formation is easily 

 differentiated from the subjacent Merchantville by reason of 

 the general absence of glauconite, except at the very base where 

 the transition from the Merchantville occupies a thickness of 

 from one toi four feet. 



The weathering of this formation is quite distinct in appear- 

 ance from that of the Merchantville, the weathered product being 

 a dove-colored or light chocolate-colored clay, which breaks into 

 innumerable blocks, large and small, frequently exhibiting con- 

 choidal fracture. The lower portion of the formation is often 

 penetrated by numerous joints, which are sometimes filled with 

 crusts of limonite. These sometimes form huge honey-comb-like 

 masses many feet in diameter and tons in weight. 



The thickness of the Woodbury clay varies from 55 feet in 

 Monmouth County to something less than that along the Dela- 

 ware. 



f'AUNA OP THE WOODBURY CLAY. 



The fauna of the Woodbury clay is extensive, and more or less 

 complete collections have been made at six localities distributed 

 from Lorillard, in Monmouth County, to the vicinity of Had- 

 donfield in Camden County, a distance of about 60 miles. The 

 essential characteristics of the fauna occur throughout the entire 

 extent of the formation. In the northern portion of the area 

 the fossils occur in ferruginous, concretionary nodules, while in 

 the more southern localities they occur directly in the clay, usually 

 in the condition of internal casts and impressions of the exterior, 

 but from one locality near Haddonfield, as shown by a collection 



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