Clarksburg hills, and to have flowed through Prospertown, Archers Corner, and thence to the sea, as now. Ivanhoe Brook, which heads north of Prospertown, is perhaps the original head of Bordens Mill Branch, but it is now the head of Lahaway Creek, tributary to Crosswicks Creek. In Bridgeton time, the drainage probably went from Clarksburg south by way of Ivanhoe Brook, Prospertown, and Colliers Mills, to Toms River. When Crosswicks Creek cut across the marl highland at Cream Ridge, and entered the region of Hornerstown and New Egypt, the drainage of Lahaway Creek and Ivanhoe Brook was diverted to the Delaware. The gravel west of Colliers Mills at an elevation of about 200± feet, was probably deposited by the stream which followed the course of Bordens Mill Branch in Bridgeton time, when the drainage from the Clarksburg region flowed to Toms River.

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The gravel west of Colliers Mills is of local trashy material derived from the Beacon Hill and Cohansey formations. contains nothing which can be referred confidently to the Cretaceous. The streams of the time had not yet cut through the Miocene of the Clarksburg region, and so had not access to older formations.

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HIGH LEVEL GRAVEL AT HEAD OF WOODS.

From Head of Woods southeast to Whitings, there is a series of hills ranging from 160 to 200 feet in height, along the divide between Toms River on the one hand, the Rancocas and Crosswicks creeks on the other. Just south of Colliers Mills, at Head of Snag, there is a gap in this divide, at the 130-foot level. This is probably part of a valley occupied by a stream for a considerable time after the epoch of Bridgeton deposition. It is probable that the drainage from the vicinity of New Egypt, and possibly from the vicinity of Jacobstown, once went eastward by Head of Snag to Toms River, and that the drainage did not assume its present course until long after the Bridgeton formation was deposited.

At Boyds Hotel, near Whitings, there is a gap in the divide at the 150-foot level. This probably represents a portion of another old valley which extended far to the west or northwest.

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The drainage of the region in the vicinity of Browns Mills, and possibly as far west as Arneys Mount, may once have gone east by way of Buckingham and Boyds Hotel, to Toms River.

This range of hills has but little gravel (1 to 5 feet), and that on the higher elevations. It seems to represent the last remnant of a gravel bed which once covered the whole area, and which was deposited on a plain of erosion developed after the Beacon Hill epoch. The region is thought to have suffered a degradation of 50 to 75 feet after this epoch, for the Beacon Hill formation originally extended over the region from Whitings to Head of Woods, at a level which is now about 250 to 275 feet above sea level.

GRAVELS (BEACON HILL?) ABOUT WOODMANSIE.

In the vicinity of Woodmansie there are many patches of gravel at various high levels. To the northward, at Whitings, they are at elevations of 170 to 200 feet; just east of Wheatlands, at a maximum altitude of 201 feet; east of Woodmansie, in the vicinity of Old Half Way, up to altitudes of 213 feet; south of Old Half Way and southeast of Woodmansie, up to 208 feet; 3 miles southwest of Woodmansie, near the railroad, up to 204 feet. There is, therefore, a considerable area within. 5 miles of Woodmansie where the surface rises to an altitude of 200 feet at many points. These higher lands are usually capped with gravel. Its depth is rarely more than 5 or 6 feet, though in occasional pockets twice this thickness is reached. It would appear that the region was once quite generally but thinly covered with gravel at the level of 200 feet, and that the gravel patches now remaining are but remnants. There are numerous gravel remnants at slightly lower levels, some of which, at least, have been displaced downward since deposition.

The correlation of these gravels is not clear. They seem at little too low for Beacon Hill and a little too high for Bridgeton. They are farther southeast than Whitings, where the Beacon Hill gravels might be a little lower than to the north and northwest. They may include deposits of both epochs, especially if the erosion between the two epochs of deposition was here but

little. The upper part of the later deposit may be as high as the lower part of the earlier.

Apparently the Woodmansie area has suffered almost the minimum of erosion since Beacon Hill time. More than any other tract in southern New Jersey, it seems to have been avoided by large streams, since that epoch. There seems therefore to be no adequate reason for excluding these gravels from either formation.

In Bridgeton time, the Woodmansie upland probably extended farther northwest than now, toward Mt. Misery; but when Rancocas and Crosswicks creeks got their heads into this region, they degraded their basins faster than the Mullica River and Toms River degraded theirs.

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CLARKSBURG TO ISLAND HEIGHTS.

Location of section. The section shown in Fig. 34' represents the general topographic relations along the divide between Toms River and Metedeconk River, the headwaters of which are close together in the vicinity of Charleston Springs. Metedeconk River was once a larger stream than now, for some of its headwaters have been captured by Manalapan Brook and Millstone River. Its earlier source was probably in the Perrineville hills.

The section is somewhat composite and diagrammatic. It passes through the 354-foot hill a mile north of Clarksburg, and thence southeast nearly to Cassville. Here the 257-foot hill and others at about 190 feet, a little out of line, are brought into the section. Near Cassville the section is offset to the northeast about 2 miles, and is then continued southeastward, parallel to the Metedeconk River to Seven Stars, near Lakewood. From Seven Stars, it follows a line roughly parallel with Toms River, to Island Heights and thence to Berkeley. Some minor details are omitted.

To the northwest, the section is carried to Disbrows Hill, Hightstown, Dutch Neck, and Princeton, and the Rocky Hill

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range, for the purpose of bringing out the relations of the Pensauken formation.

In this section the Beacon Hill gravel appears at one point only, namely, in the Clarksburg hills, where its base has an elevation of about 360 feet. This alone would give little clew to the surface in the Beacon Hill time, but from the sections of Figs. 34 and 35 (p. 136) more is known of it.

On the Rocky Hill range there is a meager scattering of gravel at levels between 300 and 400 feet. These traces of gravel are in accord with the hypothesis that the Beacon Hill formation once covered the ridge.

Bridgeton base southeast of Clarksburg.-The data for the reconstruction of the Bridgeton base along the line of this section leave much to be desired. Southeast of Clarksburg there is a series of elevations ranging from 250 feet near Carrs Tavern to 96 feet at Island Heights. The gravels on the hills, which range from an altitude of 190 feet near Francis Mills to 160 feet at Cassville and to 150 feet in the vicinity of Lakewood, are regarded as most probably of Bridgeton age.

The volume of material near Lakewood is much greater than at the 190-foot level at Francis Mills. Its elevation at Lakewood is 150 feet, more or less. In constitution it is very unlike the gravel near Clarksburg, but very similar to that at Barnegat, which is like that of Hammonton and Vineland, except for the absence of shale and crystalline material. The Lakewood and Barnegat gravels are alike in coarseness, proportions of sand and gravel, structure (for example, the long, horizontal lines of pebbles seen in section), compactness, color, cementation, etc. From Lakewood to Island Heights, the surface declines from 150 feet to about 50 feet at Toms River. Most of the surface is covered with gravel. It is doubtful if all of it is of the same age, but the differentiation of its parts, if its parts are different, is difficult. The gravel at the lower levels carries more ironstone, etc., and less soft chert, relatively, than that at the higher levels. It is possible here, in various cuts, to recognize about the same distinctions, with reference to constitution, that obtain in the Bridgeton, Pensauken, and Cape May elsewhere. It seems prob

able that these several formations here overlap one another; that is, that they are more or less imbricated.

Bridgeton base northwest of Clarksburg.-To the northwest of the Clarksburg hills, there is difficulty in identifying the Bridgeton formation and in determining the level at which it should occur. Between Disbrows Hill and Rocky Hill (Fig. 34) is the broad lowland covered by the Pensauken formation. Northwest of the Pensauken area there is a tract near Princeton, more than 200 feet in elevation. This elevation stands in about the same relation to Rocky Hill that Disbrows Hill does to the Clarksburg hills.

At at elevation of about 220 feet in the vicinity of Lawrenceville southwest of Princeton, patches of gravel are found. They are too low to be correlated with the Beacon Hill gravel, and too high for Pensauken, and for these reasons are regarded as probably Bridgeton remnants.

Near Pennington, 7 miles west of Princeton, there are bowlders, gravel, etc., at elevations of 200 to 240 feet, and this level seems to represent a rather definite former plain of degradation. The bowlders are regarded as probable remnants of the Bridgeton cover which once overlay the region.

Near Disbrows Hill, the section shows lesser hills at 160 to 180 feet. These hills are in reality a little south of Disbrows Hill, but the section shows their proper relations stratigraphically and topographically. Their gravel caps may be Bridgeton or post-Bridgeton, and their correlation is open to question.

The pre-Bridgeton surface southeast of the Clarksburg hills appears to have had an altitude of about 200 feet and to have declined to the southeast. This plain of degradation was probably developed by streams 25 to 40 miles in length. Northwest of the Clarksburg hills the pre-Bridgeton plain was probably developed by the great river which flowed through the AmboyBordentown valley, and by its tributaries. If this is so, the plain developed by this master stream should have been lower than the plains to the southeast developed by many small streams. The Delaware now has its bed down to tide level up to Trenton, 100 miles or so from the ocean proper. The larger stream of earlier