140 CLAYS AND CLAY INDUSTRY. 



represents the northwestern limit of the Miocene deposits. At 

 present they are dug at Bridgeton (191), Rosenhayn (185), Mill- 

 ville (183), Mays Landing (195), Da Costa (197), Elwood 

 (198), Window Junction (201), Woodmansie (213), Whitings 

 (212), Toms River (206) and Herbertsville (218, 219). They 

 have also been dug at Seven Stars, White Oak Bottom, north 

 of Whitings, Wheatland, Union Clay works, Tuckerton (210, 

 211), Mayetta (209) and near Cedar Grove, all in Ocean county; 

 at Mount Misery and Chatsworth, in Burlington county; near 

 Atco, Williamstown Junction and Blue Anchor (202, 203, 204), 

 in Camden county ; at Egg Harbor City, and near Centre Grove, 

 in Cumberland county. At Mayetta a tract over 700 acres in 

 extent is reported to be underlain by clay, with a thickness of 

 24 feet. 



Clay probably belonging to 1 the same formation has been ob- 

 served in the pines west of Toms River, near Davenport (208), 

 and also north of Toms River and south of White Oak Bottom 

 (207). It is also reported at South Park, Burlington county, 

 and from many other places in the pines, as indicated on the 

 map. It is entirely probable that similar lenses of clay exist at 

 many other points within this district, but their location can be 

 determined only by boring. In the absence of any natural ex- 

 posures, such as stream bluffs, or of artificial excavations, such as 

 road or railroad cuts, and in the presence of the widespread and 

 continuous covering of sand and pine forest, their location is a 

 matter of great difficulty. 



Character. — These clay lenses vary considerably from place 

 to place. They are usually somewhat sandy, particularly near 

 their borders. The upper foot or two frequently contains 

 scattered pebbles. In color they are white, yellow, chocolate 

 and black. The latter clays contain much lignite, usually, how- 

 ever, in a finely broken condition. Many of these black clays, 

 however, bum buff, Plate XVII, Fig. 1. The white clays are 

 often more or less yellow mottled near the surface, owing to the 

 infiltration of iron from the overlying yellow gravels. 



The clay beds are underlain by coarse sand, into which they 

 pass either by thin alternating layers of sand and clay or by a 

 gradual transition, the clav becoming more and more sandy. 



