Bridgeton Formation — Local Details. 6i 



times may have been near tide level still farther from the sea. 

 The pre-Bridgeton lowland on the northwest side of the Clarks- 

 burg hills, therefore, may well have been lower than the cor- 

 responding plain to the southeast. Its level near Hightstown 

 may be inferred from the facts set forth in the following para- 

 graphs. 



i. In the vicinity of Blackwood and Haddonfield, there was a 

 considerable area near the Delaware in pre-Bridgeton time, 40 to 

 60 feet lower than the major divide at Berlin and Glassboro. 

 This lower land appears to have been a lowland or rude terrace 

 bordering the ancestor of the Delaware. If this stream was at 

 tide level at that time, this bordering lowland could not have 

 been very much higher. 



The present remnants of this lowland, as located by the base 

 of the Bridgeton, have altitudes of about 100 feet at Woods- 

 town, 120 feet at Woodbury, and 130 feet at Haddonfield. If 

 these figures indicate the rise of this old lowland to the. north- 

 east, a surface projected from Haddonfield to Hightstown in 

 accordance with this slope, would have an elevation of about 

 200 feet at the latter place; but without further evidence, it 

 would be unsafe to assume that the plain of Bridgeton deposi- 

 tion at Hightstown was at this level. The data, however, do 

 indicate that the pre-Bridgeton lowland rose to the northeast 

 from the Delaware. 



2. The 200-foot divide in the vicinity of Freehold apparently 

 goes with the 140-foot surface at Glassboro beneath the Bridge- 

 ton gravel, and appears to be a part of the same plain sloping 

 southward. 



The lowland along the Delaware, in the vicinity of Barns- 

 boro and Blackwood was apparently 40 to 60 feet lower than 

 the plain at Glassboro and Daretown, farther back from the 

 main stream. Similar relations appear to have existed in the 

 vicinity of Freehold, and the Hightstown plain was perhaps 

 50 to 60 feet lower than the Freehold plain at 200 feet. If the 

 remnants of the pre-Bridgeton plain at Freehold are now found 

 at 200± feet, the remnants of the pre-Bridgeton plain at Hights- 

 town, if they exist, should be 50 or 60 feet lower. 



