worked. It is not possible to correlate these clays with any of the beds in the Woodbridge area.

In addition to the Dogtown clays, pits have been opened in the Raritan formation at other points near Trenton, but they are no longer worked. Clay occurs in the bluff along the Delaware river south of Trenton and north of Crosswicks creek, particularly on the property of Dr. C. C. Abbott and P. E. De Cou. Some of this clay was at one time taken out by tunneling into the hillside, some drifts being 200 feet long, but owing to the cost of timbering it was abandoned. A black sandy clay, 6 to 7 feet thick, is exposed beneath 10 or 15 feet of Pensauken gravel in a ravine west of Yardville (107), but it has not been worked.

BORDEN TOWN.

From Bordentown to Kinkora the base of the Clay Marl I is found at the top of the bluff along the river, and black lignitic clays and interbedded sands of the Raritan formation form the basal portion. Landslides and washes have very generally obscured the section, but occasionally fresh faces are visible. About one-half mile south of the Bordentown depot the following section was reported by Drs. Cook and Smock.1

Section near the Bordentown Depot.

(1) Yellow sand and gravel,

(2) Clay marl (greensand),

8-10 ft.
5 ft.

(3) Black, sandy clay full of pyrite and lignite, alter

nating with layers of white quartz sands,...... 35-40 ft. (4) White quartz sand at the level of the track (10 feet A. T.)

At White Hill, at the north end of the forge building, they reported the following2:

Section near White Hill.

(1) Yellow earth and gravel,

8-10 ft.

(2) Clay Marl,

6 ft.

(3) White sand containing red oxide of iron crusts,
(4) Black, sandy clay alternating with thin layers of

...

12 ft.

sand, .....

12 ft.

(5) White sand from railroad track level to tide level,..

10 ft.

Forty distinct layers were counted in a vertical section of 3 feet in No. 4, while above them was a single bed of clay 3 feet thick. This illustrates the great variation in thickness of the clay and sand layers.

At S. Graham & Co.'s brickyard (112), the same thin-bedded, black clay, with fine laminæ of white sand is dug in pits east of the wagon road, while along the railroad more sandy beds are exposed. The horizontal variation from clay to sand is well brought out in these banks (Plate II, Fig. 1). At Dobbin's bank, Kinkora (113), a few feet of the same black laminated clays are shown, but the greater portion of the clay there dug belongs to the overlying Clay Marl series.

FLORENCE.

Below Kinkora the course of the river is more to the west and it crosses obliquely the outcrop of the Raritan formation towards the base. The immediate consequence of this is that, in the bluff below Kinkora, lower beds of the formation are exposed, so that at Martin's brickyard (115) a tough, white and red-spotted plastic clay is found in pits in the lowest portion of the yard. This clay belongs below the black laminated clays of S. Graham & Co.'s bank, but the interval between them is unknown. A black clay is also dug in another part of Martin's yard at a higher level. It does not, however, belong to the Raritan formation, but is of much later age, being a Pleistocene clay similar to that found at Fish House (p. 133). For a mile or more above Florence the river flows at the foot of a high bluff, in the lower portion of which white and red clays outcrop at numerous points. They were somewhat extensively worked twenty-five or thirty years ago, and the following sections are given in the Clay Report of 1878.

In other portions of the bank, however, the section was quite different.

Section at Henry I. Tinsman's clay bank-300 yards from Eayre's.

(1) Sand,

(2) Black clay with lignite,

15 ft.

5-8 ft.

(3) Bluish white clay with some included masses of red
clay in it, down to tidewater,

12 ft.

These pits are no longer worked, but E. M. Haedrich has made extensive excavations in the bluff a mile northwest of Florence station, where both Pensauken and Cretaceous gravel and sand are worked. Several feet of Clay Marl I are here exposed beneath the Pensauken and above the sands of the Raritan formation. Incidentally some beds of white and red clay are also taken. A black sandy clay, probably corresponding to the laminated clay at S. Graham & Co.'s brickyard, is reported in wells around Florence and Florence station at depths of 15 to 25 feet.

BURLINGTON.

White and red plastic clay occurs 2 miles east of Burlington, along Assiscunk creek, on both banks of the river, on property belonging to Mr. Joseph P. Scott (120) and Mr. Hays (121). On the north bank it occurs in low ground covered by a few feet of sand; on the south bank it is seen at the base of the creek bluff, overlain by yellow sand at an elevation of 12 or 14 feet above the creek. Stripping of 20 to 25 feet will be encountered in working back into the bank for any distance, but considerable clay can be dug along the creek without much stripping. Samples of these clays have been tested, the results being given in Chapter XIX, under the clays of Burlington county.

BRIDGEBORO.

The clay dug by J. W. Paxon & Co., at Bridgeboro, on the south bank of Rancocas creek (132), belongs to the Raritan formation. At the western openings a red-mottled clay, with some yellow and some white masses, was exposed to a depth of 10 feet, below 8 or 10 feet of Pleistocene sand and gravel. The