160 CLAYS AND CLAY INDUSTRY. 



often distinctly laminated. Fossils are quite abundant, particu- 

 larly in the glauconitic portions, and are more frequently found 

 than in Clay Marl II. 



The weathered portions of this bed are very characteristic. 

 When marly they form an indurated, cinnamon-brown earth, in 

 which the small black grains of marl are distinctly seen. When 

 more sandy, the weathered portion has a peculiar "pepper and 

 salt" aspect. The weathered part of the nonmarly portion is less 

 characteristic, being sometimes a chocolate color and resembling 

 the weathered portion of Clay Marl II. Where sections do not 

 occur, the bed may be traced most readily by the rusty cinnamon 

 brown color of the weathered basal and upper portions, 



Stratigraphic relations. — The transition from Clay Marl I 

 to Clay Marl II is generally accomplished within i to 3 feet. 

 When exposed in section there is rarely any question as to where 

 the division between the two formations should be made. The 

 base of this bed is the base of the Clay Marl series. Wherever it 

 has been seen it rests upon a loose, coarse, lignite-bearing sand 

 or a sand with thin seams of black clay. Not infrequently the 

 upper few inches or a foot of this sand is cemented into an 

 ironstone. At some pits where this clay is dug it is only neces- 

 sary to break through this crust to the loose sand beneath to 

 secure perfect drainage (PI. XVIII, Fig. 2). 



The contact of the black marly clay or its rusty-brown weath- 

 ered phase and the Raritan sand beneath is shown, 1 ) in the 

 high bluff on the shore of Raritan bay northeast of Cliffwood; 

 2) at the clay pits on the west side of Matawan creek; 3) in 

 several ravines between Morristown and Cheesequake (Jackson- 

 ville) ; 4) in the vicinity of Jamesburg; 5) at several points 

 near Bordentown and Kinkora; 6) on Pensauken creek north of 

 Maple Shade station; 7) at Budd Brothers' brickyard, Camden; 

 8) and at numerous other points southwest of Penns Grove. Irr 

 Monmouth county heavy beds of black clay occur in the Raritan, 

 not many feet below the contact with the Clay Marl. These 

 beds have sometimes been included in the Clay Marl series, but 

 that they do not belong there is at once apparent to anyone who 

 makes a careful study of the two> series. This is particularly the 

 case if the contact between them is traced from the southwest, 



