138 Quaternary Formations of Southern New Jersey. 



rather fine, most of the pebbles being less than an inch in diam- 

 eter, though cobbles occur, and rarely a bowlder. Among the 

 pebbles are bits of red shale and granite. Most of the sand is 

 yellow and brownish in color, but some of it is white; some of 

 it is arkose. 



West of Bonhamtown, on Mill Brook, exposures have been 

 seen which are especially till-like, — so much so as to lead one in- 

 stinctively to look for striated bowlders, but none have been 

 found. Locally red shale constitutes 75 per cent, of the whole. 



Another remnant of Pensauken occurs at Sand Hills, east of 

 Bonhamtown, and still other cuts and pits show it to be present 

 beneath the glacial drift near Woodbridge and farther south. 

 Thus a mile or so southwest of the Woodbridge depot, in the 

 140-foot hill, 40 feet of Pensauken sand has been seen in section. 

 The sand is of the arkose type, yellowish to white in color, some- 

 what like that at Old Bridge. There is little fine gravel here. 

 The material differs from that at Bonhamtown in being more 

 arkose a«d less gravelly. 



At Metuchen, the Pensauken has been seen well exposed in 

 railway cuts northeast of the depot (Perth Amboy line). Quartz 

 pebbles make up much of the gravel ; but quartzite and sand- 

 stone are present both as gravel and in larger pieces. Pieces of 

 red shale are common, as are small bits of granite, thoroughly 

 decomposed. In some places the composition of the material 

 suggests glacial drift, but it is in striking contrast with the last 

 glacial drift a few rods to the north. 



A mile northeast of Metuchen depot, and three-fourths of a 

 mile east of south of Menlo Park, Pensauken with a distinctly till- 

 like structure has been seen beneath glacial drift; but glacial 

 stones were not found in it. 



In the area north of the Raritan and east of the Pennsylvania 

 Railroad, the Pensauken has two somewhat distinct phases : the 

 one, arkose sand ; the other gravel in which red shale and granite 

 are prominent. Locally there is much clay with the gravel and 

 bowlders, and the structure is somewhat till-like. Though the 

 two phases have not been seen in section, general relations sug- 

 gest that the sand was deposited first, and the coarser material 

 later; but that in time of origin, the two were not far apart. 



