Bridgeton Formation — Local Details. 43 



tially the same, except that bits of shale and crystalline rock 

 become fewer to the south, and the gravel becomes finer. The 

 basal bed of coarse material is generally present. 



The base of the formation here has some irregularities of a 

 small sort. Thus south of South Vineland and east of Clayville, 

 at the clay pits of the Globe Fireproofing Company, the surface 

 of the Cohansey formation was seen stripped of the Bridgeton 

 which once overlay it. The surface of the clay was marked by 

 numerous depressions, some of which were like shallow gullies, 

 and some were shallow depressions without outlets. Their forms 

 suggested scour holes developed by running water, or, in some 

 cases, depressions made by the overturning of trees. There are 

 irregularities of other sorts, indicated by the fact that the altitude 

 of the base of the Bridgeton varies 30 feet or more within the 

 distance of a mile. This was seen in the vicinity of Clayville. 

 Irregularities of base were also observed about Millville. 



Between Manantico Creek and Manumuskin Creek. — A small 

 area of the formation appears 2 miles southwest of Richland, a 

 larger area on the divide between Hanges Bridge and Bennetts 

 Mill, and several smaller areas on the summits south of Cossa 

 Boone's Branch. The surface of the formation declines from 

 a maximum of 120 feet at the north, to> 70 at the south, and the 

 decline of the base is from about 90 feet at the north to 60 feet 

 at the south. The slight exposures show no distinctive features. 

 The Cohansey sand in this vicinity is cemented in many places. 



Between Manumuskin Creek and Tuckahoe River. — The 

 Bridgeton appears on the divide between these streams most of 

 the way from Richland to the latitude of Fries Mills. Farther 

 south there are smaller areas on the upland east of Manumuskin 

 and Bricksboro. As in the preceding cases the altitude is greatest 

 at the north and least at the south, the decline being from about 

 90 feet at the north to about 50 feet at the south. About Rich- 

 land and Doughty' s the formation is orange 1 colored sand and 

 gravel, with occasional cobbles, cemented in some places. The 

 surface of the formation is more or less covered with eolian 

 sand. 



