Clayton, W. Woodford, History of Union and Middlesex Counties. p. 422-431.

CHAPTER LX.

THE CLAY DISTRICT OF MIDDLESEX COUNTY.*

Topography.— The clay district, which is the chief subject of this report, includes the portion of Middlesex County which lies along the Raritan and South Rivers and the Woodbridge and Chesquake Creeks and extends from Woodbridge on the north to the Mounmouth County line on the south, and from Staten Island Sound and Raritan Bay on the east to Martin’s Dock and the mouth of Lawrence Brook on the west its boundaries are as follows: Beginning at the northeast on Staten Island Sound near the mouth of Woodbridge Creek, the line runs west-southwest up the creek till opposite Edgar Station, on the Woodbridge and Perth Amboy Railroad, which is three-quarters of a mile north of Woodbridge; thence from the creek running west and southwest near the old Woodbridge and Metuchen road, and intersecting the Metuchen and Bonhamtown road a half-mile north of the latter village; thence southwest through Piscataway to Martin’s Dock on the Raritan River; south of the Raritan River its western limit may be said to be defined by Lawrence Brook and the Old Bridge and New Brunswick turnpike; the southern boundary is not plainly marked, but it may he approximately described as running from Old Bridge to Jacksonville and thence to the Monmouth County line near Ran tan Bay shore; and the waters of Raritan Bay and Staten Island Sound, being the State line,** limit it on the east.

On the northwest the clay district joins that of the red shale and sandstone, and the frequent outcrops of the latter make the location of the northern boundary of the clay easy and accurate. Towards the west the boundary is entirely arbitrary, the later geological deposits, over which the Old Bridge and New Brunswick turnpike runs, being without any breaks, and effectually concealing the underlying formations. Indeed, it is probable that the equivalent of the clay is not limited by the boundary above given, but that, like all the other deposits of the cretaceous formation, it extends entirely across the State in a southwesterly direction to the Delaware River and beyond. In the flat and sandy country south of the South River, and stretching east as far as Jacksonville, yellow sand and gravel drift reach down to tide-level, and so effectually discourage explorations for clay that this boundary must be considered the limit of the district in which clay can be profitably dug, rather than the end of the beds of clay. From Jacksonville to the bay shore the outcropping clay-marl accurately defines the southeastern margin of the clay district. The map accompanying this report shows the whole of this district which produces clay, including all the pits of the county and of the adjoining parts of Staten Island in which fire-clay or stoneware clay is dug; but it does not exhibit the whole area of the county in which clay may possibly yet be found. The belt of country underlaid by the plastic clays extends entirely across the State, and includes an area of three hundred and twenty square miles. In this area it is possible much valuable clay land may yet be found which can be worked to profit. The area of the clay district of Middlesex County, within which is included all the clay pits at present worked, is only sixty-eight square miles.

The map of the clay district which accompanies this report exhibits the above-described boundaries and areas on a scale of three inches to a mile. It will be further described in its relations to topography and structural geology.

Although this district borders the tide-waters of Staten Island Sound and Raritan Bay, and is intersected by the tide-waters of the Raritan and South Rivers, and belongs in the general Atlantic slope of the country, it has not the flat surface or general long seaward slope which are such marked features of most of the land along our coast. On the contrary, the surface is uneven, and its average elevation is quite as great as that of the red sandstone country on its northwest border, or the marl region on its southeast. North of the Raritan River nearly all the upland has an elevation exceeding thirty feet, and fully one-third of it is over one hundred feet above tidewater level. This area is subdivided by a series of hills or flattened ridges, which extend southeast from the Short Hills near Metuchen to Perth Amboy. The Perth Amboy and Metuchen road runs almost level high up on the side of this elevated ridge. From this elevated ground as the water-shed the drainage is northeast and east into Woodbridge Creek and Staten Island Sound, and southward into the Raritan River. Poplar Hill is the highest point in this ridge or chair of hills, and the highest in the district, being two hundred and forty feet above tide-level. From Ford’s Corners westward to Bonhamtown, and thence southwest to Piscataway, the old road runs on high ground most of the way about one hundred feet above tide Bordering the Sound and along Woodbridge Creek there is a narrow fringe of tide marsh. The largest body of tidal meadow, however, is along the Raritan River. That on its north side extends the whole distance from Martin’s Dock to the Crossman Clay Company’s works, and is from a half-mile to a mile wide, and nearly five miles long. On the south of this stream there is but little tide marsh on the shore of the bay; Chesquake Creek is widely bordered by tide marsh from its mouth to its head; there is a fringe of marsh along the south shore of the Raritan, between South Amboy and Kearney’s dock, and smaller patches from there up to Sayreville, and a much larger tract above Sayreville about the mouth of South River, and stretching up that stream nearly four miles. The area of the district which is tide marsh is as follows in acres: 

The surface of the quadrilateral area bounded by these streams and Raritan Bay is nearly all forty feet and upwards above tide-level, and a large part of it is about one hundred feet high, while a number of hilltops are from one hundred and forty to one hundred and eighty feet in height. These hills are irregularly grouped. One ridge of one hundred to on hundred and eighty feet high can be traced from Sayreville southeast, east, and again southeast nearly to Chesquake Creek. The Burt’s Creek and Jacksonville road runs a little east and northeast of the crest line of this ridge. West, southwest, and south from South Amboy most of the surface is between one hundred and one hundred and forty feet high. The Camden and Amboy Railroad cuts through this high ground near the Sayerville road, ascending from the depot at South Amboy to an elevation of one hundred feet near this road, and descending a little near the clay pits of W.C. Perrine and E.R. Rose, and again running up to one hundred feet across the ridge near the Burt’s Creek and Jacksonville road. It runs over three miles on the water-shed between the stream flowing north and west into the Raritan and South Rivers, and those flowing east and south into the bay and Chesquake Creek. The slopes of the upland towards the Raritan and South Rivers are comparatively gentle, and terminate, except in a few cases, in tide marshes. South of South Amboy, along Raritan Bay and up Chesquake Creek, the upland is high quite to the water or marsh, and forms bluffs that mark clearly the upland from the marsh. The New, York and Long Branch Railroad runs at the base of these bluffs from South Amboy to the Chesquake Creek at Morgan Station.

Table of Elevations in the Clay District of Middlesex County, taken with an Engineer’s Level.— The following table of elevations, ascertained by Leveling, gives the heights at many easily identified points. The figures give the elevation in feet above mean high-water level:

ELEVATIONS OF EACH OF THE CLAY-BEDS AT VARIOUS POINTS IN THE DISTRICT. 

 SOUTH AMBOY FIRE-CLAY BED. 

The drainage of this clay district has been already described in connection with its surface elevation. It is so limited in extent that there are no large streams wholly within its bounds, and yet it is remarkably intersected by tide-water and navigable channels. Thus in this area of about sixty-eight Square miles there are about thirty miles of shore fronting on navigable water; or, counting both sides of the Raritan as high up as Sayreville, and excluding the more tortuous bends of the Raritan and South Rivers and Chesquake Creek, there are twenty-five miles of water-front. So that there is not a point in the district three miles from navigable water, and of the one hundred clay, kaolin, and sand pits none is more than two and a half miles away from such waterfront. The advantages of this remarkable location for development of such a country are plainly shown by the rapid growth of its industries.

The tributaries of these rivers and creeks are small and unimportant, although most of them for short distances are small tide-water inlets, bordered in some cases by tide meadows, and some of them are capable of being improved as canals or basins.

The character of the surface and soil throughout this clay district is so varied that detailed description would fail to convey a distinct idea of its manifold phases. And yet nearly if not quite all the upland area can be described in two clearly characterized groups. These two groups of soils and superficial deposits mark two kinds of and two periods of the drift. These are (1) the northern or glacial drift, which is composed of fragments of the red shale and other northern rocks spread unevenly over the surface; (2) the older (southern?) yellow sand and gravel drift, derived apparently from some more southern source, and containing no red shale drift whatever. The former is the more recent of the two, and is found resting at many points upon the latter, and both uncomformably upon the beds of clay, etc. The district north of the Raritan is mostly covered by the former, and that south of the Raritan has only the latter kind. The yellow and gravel drift is found to some extent north of the Raritan.

1. GLACIAL DRIFT.— No attempt has been made to trace out all the sinuosities of the limits of this surface formation. The general outlines are as follows:

Staten Island Sound on the east, Raritan River on the south, and on the west a line drawn from the works of the Crossman Clay and Manufacturing Company north-northwest to the Sand Hills, and thence west near Bonhamtown to the limits of the map. Northward this connects with the Short Hills and the red shale country. It will be thus seen that this drift covers or occupies the tongue of land running southeast from the Short Hills to a point between the Sound and the Raritan River, forming Poplar Hill and the high ground thence to Perth Amboy. It must here be stated that the Sound is not its eastern limits, as the same drift covers nearly the whole of Staten Island, and there is no difference in the materials as seen at Perth Amboy or Tottenville on the opposite shore. No shale or sandstone is to be found south of the Raritan River and east of the South River, and the former at Amboy sharply divides the two surface formations. This drift is cut on the line of the Easton and Amboy Railroad at Ford’s Corner, and at several points, between that place and Perth Amboy. It is best exposed, in its relations to the yellow sand and gravel, in the feldspar banks of Charles Anness & Son, and in the Woodbridge and New Brunswick road, near William H. Berry’s bank. It can also be seen in the cut on the Easton and Amboy Railroad, half a mile south of Ford’s Corner.

This red shale drift belongs to the true northern drift of the glacial epoch, which is seen covering nearly all of our more northern territory. This portion, thus locally described, must be considered as part of the southern end of the great sheet covering the continent, and the city of Perth Amboy stands on the southernmost point Of this particular drift bank. The red shale material, the predominating and characteristic constituent in this mass of drift, gives character to the surface of the country, which resembles somewhat the country to the north and west, where the red shale crops out in place. The soil has that peculiar purplish-red color, and is in marked contrast with the sandy surface towards the west and south. The forest on this drift area is also quite different from that growing on the sandy and gravelly loam surfaces. There is less chestnut and no pine, both of which trees are common and make up most of the wood found growing south of the Raritan River. From these statements it is evident that the boundary of this drift is easily and accurately traced.

The matrix of this drift consists of red shale in the form of small fragments and as fine red earth. In this the pebbles, cobble-stones, bowlders, and other rock masses are inclosed, without order and in all possible combinations. Bowlders and pebbles and fragments of red and bluish (indurated) sandstone and of trap rocks are very abundant. Gneiss, granite, and syenite are less abundant; the conglomerates and slaty grits of the Greenpond Mountain (Potsdam) series and the magnesian and Trenton limestones are of much rarer occurrence. Large bowlders are quite common, so much so that their removal in clearing new ground for tillage is laborious and quite costly. Many of them are large enough for quarrying into building stones. One on Miss Gale’s land, three-fourths of a mile west of Woodbridge, and a short distance south of New Brunswick turnpike, was twenty-five to thirty feet in diameter, and was used for bridge abutments on the Easton and Amboy Railroad. In Melick Bros’ clay bank, near Woodbridge, a granite block ten feet in diameter was found, lying with its polished and striated side down and imbedded three feet in the fire-clay bed. Near Patrick Miles’ house, west of Woodbridge, there is a trap rock bowlder whose dimensions out of ground are fifteen by ten by five feet. Others nearly as large might be cited, but they are not uncommon, although growing scarce as the country is more cleared up and farmed or worked for its clays. Bowlders from one to three feet in diameter are abundant, both in the drift-bed and on the surface. Occasionally thin and irregular layers of white, sandy clay and clayey-like pebbles occur in this drift. These are, however, of very limited extent and not common.

The surface of much of the area occupied by the drift is remarkably uneven. The hills are irregular in outline and of uneven slopes, and sink-holes and small ponds are numerous. These irregularities of the surface are striking features in the higher grounds west and southwest of Woodbridge, in what may be termed a continuation of the Short Hills.

The thickness of the red shale drift as cut in mans places does not exceed twenty feet, but in Poplar Hill there must be a much greater thickness, possibly more than a hundred feet. The average or mean thickness may be put at twenty feet. An examination of the table of elevations of the clays, kaolins, feldspars, and fire-sands, and a comparison of these heights and the heights of the surface at these places shows that there is not anywhere more than forty feet of drift, excepting in Poplar Hill. So far as excavations indicate it is frequently quite thin, sometimes amounting to little more than a soil and subsoil. This is more particularly the case towards the southeast and near its boundary lines, or where the sheet thins out and disappears.

That this drift is a part of the great northern drift and of the glacial epoch is evident from the nature of the materials. The large and numerous bowlders in it belong to rocks whose outcrop is to the north, and these occur in numbers proportional to the nearness of such rock formations. Thus the trap rocks and sandstones are in excess over the gneiss and conglomerates. Then the great mass of shaly material has certainly not traveled far, as much of this is in the form of fragments, which are incapable of long transportation without being reduced to earth. This character of constituent materials and entire absence of all sorting or stratification corresponds with what it observed in the great northern drift elsewhere. No organic remains have been discovered in it, although it has been so largely excavated and at so many points.

2. YELLOW SAND AND GRAVEL.— This so-called sand and gravel drift includes all the more or lea sandy and gravelly layers which form the, surface materials or superficial covering of this clay district outside of the lines above given as the boundaries o the more recent red shale or northern drift. As has already been stated, it underlies much of the latter and extends north and northwest beyond the limit of this district. In all directions it goes beyond the comparatively small area represented by the map. The almost endless gradations of sand, sand barns, gravel, gravelly barns, etc., generally of yellowish color, but with, many other shades accidental to the surface, are embraced in this formation. It is not only thus marked by the general character of its material components, but more definitely by the sorted or stratified arrangement of these materials, a characteristic which everywhere distinguishes it from the unsorted red shale drift. And it might very appropriately be termed the stratified drift. Towards the northwest, between Bonhamtown and Martin’s Dock, some red shale earth and fragments and bowlders appear in it, as if there had been a mingling of materials by alternate currents carrying shale and sand and gravel. Excepting on the northwest border of this district, there is a remarkable absence of shale in this formation. And this is another of its distinguishing features.

This sand and gravel or stratified drift is found as a surface covering, unconformably resting upon all the clay and other beds of the plastic clay series, excepting in the area of the red shale drift, where it is over-laid by the latter.

The thickness of this surface formation varies exceedingly from point to point, even within the limits of a single clay bank. In those about Woodbridge and north of the Raritan River it ranges from one to thirty feet, or possibly in rare instances even more widely. In William P. Edgar’s clay bank it is thirty feet thick, and the red shale drift is wanting, this forming the surface. In the bank of William H. Berry, a few rods southwest of Edgar’s, it is cut twenty to twenty-five feet thick under six feet of red shale drift. A few rods west of this and on the same property the latter rests immediately upon the top black clays. The same irregularities and breaks appear in it in the Mutton Hollow clay banks, west of Woodbridge, and in those of the Salamander Works and others, north of the New Brunswick road. And the two in their relation to each other and in their varying thickness are beautifully exposed in Anness’ feldspar bank, in E.F. Roberts’ bank, near Eagleswood, in the cuts of the Easton and Amboy Railroad, in the east bank of the Crossman Clay and Manufacturing Company, and at many other points which might be mentioned, since most of the digging for clay about Woodbridge has to penetrate both of these drift formations. The average thickness may be put at ten feet. In the clay banks at the Sand Hills and along the north shore of the Raritan River the thickness is from four to twenty-five feet. Here it forms the surface material. South of the Raritan it appears to be thicker, ranging from fifteen to forty feet in the several clay banks from Sayreville to South Amboy. At the sand bank of Maxfield & Parisen, in South Amboy, it is at least thirty feet; at Otto Ernst’s clay-mines, near Chesquake Creek, it is about forty feet thick. From the elevation of some of the hills and ridges in the district southwest of South Amboy (one hundred and forty to one hundred and eighty feet), the maximum thickness of this sand and gravel is thought to be not less than one hundred feet.

The materials of this formation, whether sand, gravel, or less rounded rock fragments, are always stratified. The lines of stratification or layers are sometimes horizontal, but frequently they are seen to be wavy or gently undulating. The dip or inclination of these laminae or layers is not uniform in direction. A prevailing dip towards the north west, as might be expected, is not shown by the observations. This sorted arrangement appears in the layers of sands, gravels, etc., although these layers are not, generally, persistent to any great distance, but taper out and are then replaced by others. In the examination of the surface of the country a marked feature is nearly everywhere observed in the gravelly hills and crests of ridges and more sandy valleys and depressions. This may be owing to some systematic arrangement of the gravel and sands, but more likely the result of surface drainage, which, operating through ages, has carried down the more easily transported sands and left these gravelly accumulations in the shape of hills and ridges such as we now see. The sand and gravel generally alternate, but irregularly, and in some places then are thick beds of sand without any lines of gravel, as for example, at the clay banks of Sayre & Fisher George Such, Messrs. Roberts, and the sand bank at South Amboy. Very frequently a thin gravel stratum a few inches thick, is seen lying immediately upon the clay. The sand-beds generally exhibit a double system of lines or oblique lamination, known as cross stratification. This can be seen at nearly all of the clay banks on the south shore of the Raritan, from Sayreville to South Amboy. The sand is mostly fine white to a yellowish-white granular quartz mass which is in some layers mixed with earthy matter. On the north side of the Raritan there is less sand and a larger proportion of earth and gravel. Quartz constitutes nearly the whole of the yellow sands, and most of this is in the form of grains and pebbles of white to yellowish, transparent, translucent, chalcedonic varieties. Some black grains of hornblende and very small, angular grains of magnetite occur with the quartz. In some places these grains are cemented together by oxide of iron, making a friable, stony mass. Fragments of feldspar are rare; am most strange is the general absence of mica from these yellow sands and gravels. It does occur in places, as in Whitehead’s moulding-sand, east of Sayerville and in the South Amboy pits. This absence of so common a mineral and rock constituent may, perhaps, be suggestive of the source of the material found in this drift. In the vicinity of Piscataway, and at Weidner’s cut near Martin’s Dock, both round and angular fragments of red shale are quite abundant in this formation. This exceptional occurrence of the shale is also seen farther southwest, beyond the limits of this map, and always near the southeast border of the shale outcrop. But here the deposition was in water, and a mixture of materials was such as would be expected. Farther east the glacial action carried the red shale farther south and covered the stratified drift, and in that manner made a marked line between the two surface formations.

Wherever the white sands of this formation constitute the surface the soil is light and poor, and the timber is mainly yellow pine, chestnut, and scrubby oak. The gravel has more earth in it, and makes a tighter and better soil. But as a whole the area occupied by this sand and gravel formation is quite inferior as a soil to the red shale drift north of the Raritan River. As these formations make the soil, their occurrence explains the differences so marked in this district, not only in the natural soil itself but in its forest covering. And much of the general development of the agricultural wealth of this part of the State is also due to this occurrence of the northern drift. The mouth of the Raritan River also owes its place to the glacier whose foot terminated at Perth Amboy. So that the glacier of the past geological age has left an impress upon this country which all subsequent tillage and improvement has not effaced.

This formation has been described as drift. It must not be confounded with glacial drift, as its origin was due to water. Its stratification, its lines and layers, indicate that flowing water and not ice was the moving power. And these alternations of pebbles and sand show that there were great changes in the force of the currents that carried them. The dip of these layers is not at all uniform, although several to the northwest have been observed. These may point to a northward movement of these currents. The general absence of red shale also points to a southern origin. Again the prevalence of pebbles, of mottled white and chalcedonic quartz, and of a reddish variegated quartz, unlike any known rocks to the north or northwest, and the existence of rolled fossils, more abundant than in the more northern gravels and true bowlder drift, all point to a southeastern origin,— a wash or drift from lands now under the waves of the Atlantic. Possibly the same continent furnished the materials for the older beds below, the clays, kaolins, and fire-sands, and this in part gravelly formation may have been the last of the successive floods that came from that direction. If so there must have been a long interval between the deposition of these clays and this drift, since these, as well as the more recent green-sand marl-beds of the cretaceous and tertiary ages, are all alike covered unconformably by it. The glacial drift came later and partly covered this, but as to the length of time between the two formations we have no data for knowing. As no fossils have been found in the older sand and gravel drift, excepting the rolled pebbles and fragments, it is impossible to determine its age. It may belong to the later tertiary and have preceded the glacial age. It is hoped that future explorations in many localities may result in the discovery of some remains which will enable us to determine its place in the geological series, and also point more conclusively to the source of its materials.

In this notice of the surface these two drift formations have been described as constituting the whole of the area of this clay district. They do not, however, form the whole surface, since there are here and there small, isolated outcrops of the several clays, kaolins, feldspars, and fire-sands. These are, as it were, little islands in the great sea of drift. But these outcrops are of so limited extent, and they have been so nearly all dug out for their materials, that they are altogether insignificant so far as surface features are concerned.

There is one other outcrop deserving attention, not so much from its size as its geological importance, this is the red shade hill in Perth Amboy township, one and a half miles northwest of Perth Amboy, and about a third of a mile east of the Woodbridge and Perth Amboy road. This outcrop of shale is not more than an eighth of a mile in diameter, and is surrounded on all sides by drift. The shale has a northwestern dip and appears to be fast rock. It is probably an elevated point in the floor, on which the clays and drift have been successively, deposited. And it was probably never covered by them, or at least not by the clay and feldspar bed. The drift may have been removed by subsequent denudation. This hill or outcrop of shale in situ is at least two miles from any other, or from the southeast border of the shale formation, and appears to be an outlier from the main body.

The tidal meadows have already been referred to in the above general description of the surface of this clay district. They constitute the more recent alluvial formation. The boundary lines of such meadows are easily traced, and are represented on the map. This alluvium rests unconformably upon the older formations. Very generally there is either red shale drift, or the sand and gravel under the meadow mud. At a few points valuable clays have been found a few feet beneath the surface of the tide meadows. The depth of the workable deposits below tide-water level and the expenses of raising both water and clay from such pits have retarded the examination of such ground for clay, and consequently only a few pits have been dug in the meadows, and these are near the upland border. The depths below mean tide-level at which clays have in several places been discovered show that the beds are continuous underneath the meadows and the Raritan River. It is only the difficulty and expense of contending against water that hinders the open big of clay pits at any proper place in these meadows. The beds of clay were deposited before the Raritan had cut its present channel to the sea.

Geology.— The geology of the clay district will be best understood by a general review of the geology of the State in which it occurs, and of the geological formations which are associated with it. For this reason we here present a condensed statement of the geology of New Jersey.

Nearly all the great geological classes of rocks and earths are represented in this State. Its oldest rocks make up the mountain range which crosses the northern part of the State from northeast to southwest in parts of Sussex, Passaic and Bergen, Warren and Morris, Hunterdon and Somerset, and which is known in New York as the Highlands, in Pennsylvania as South Mountain, and is here without any general name, but its individual ridges are known as Ramapo Mountain, Hamburg Mountain, Schooley’s Mountain, Trowbridge Mountain, Watnong Mountain, Musconetcong Mountain, Scott’s Mountain, Marble Mountain, and others. The newer geological formations lie upon each side of this central ridge and run parallel with it, the Silurian and Devonian limestones and other formations being mostly in a broad belt upon its northwest side, and a little in its valleys; the Triassic red sandstone adjoins it in a broad belt on its southeast side; the Cretaceous clays and marls stretch across the State in a belt just southeast of the red sandstones; and the Tertiary and the Recent formations lie southeast of the marls. The Azoic, Cretaceous, Tertiary, and most of the Recent have a prevailing dip towards the southeast, while the Silurian, Devonian, and Triassic mostly dip towards the northwest.

The boundaries of the Middlesex clay district are as follows: The northwestern boundary, beginning at Woodbridge Neck, on the shore of Staten Island Sound, passes just north of the villages of Woodbridge and Bonham town to the Raritan River, a few rods below the mouth of Mill Brook. Then crossing the Raritan it is easily traced along the south side of Lawrence Brook, and at distances varying from a few rods to a quarter of a mile from the stream to the bend of the brook a mile west of Dean’s Pond. From there it can be traced in almost a straight line to the Delaware and Raritan Canal, half-way between Clarksville and Baker’s Basin, and then near the line of the canal to Trenton and the Delaware River. From Trenton to Salem the Delaware marks the northwestern and western boundary, with the exception of some limited patches of marsh and alluvium along the river. Its southeast border can be traced from the shore of Raritan Bay, a little south of Chesquake Creek, in a southwesterly direction in a line passing north of the village of Morristown, and on just south of Jacksonville; then across the country by the house of the late Parker Brown to the little village called Texas, on the Matchaponix Creek; and from thence directly on, passing about a mile south of Jamesburg Station, and crossing the Camden and Am boy Railroad near Cranbury Station, it passes about a half-mile north of Hightstown, and thence in a line a half-mile north of the railroad to the mouth of Crosswick’s Creek on the Delaware at Bordentown. It follows the bank of the river to Kinkora, from which place it is extremely difficult to trace it with accuracy, the characteristic clays being entirely hidden by superficial deposits and soil, except in the banks of the streams. Guided by these marks the line has been drawn. It follows near the line of the railroad east of Florence; a half-mile east of Burlington crosses the Rancocus a mile above Bridgeboro’, and the Pensauken some distance above Cinnaminson bridge; it comes to the bank of the Delaware again at Gloucester City; it passes back of Red Bank, crosses Woodbury Creek a mile above its mouth, Mantua Creek near Paulsboro’, and Raccoon Creek a mile above Bridgeport; thence it continues in the same direction to the Delaware near Pennsgrove.

The area comprehended within this formation is three hundred and twenty square miles.

The materials of the clay formation are earthy, and no rocky or stony layers or beds are to be found in it. There are some small places in which the sand and gravel have been cemented with oxide of iron sufficiently to form a rough building stone, and concretions of clay and oxide of iron of a stony hardness are found in some of the clay beds, but the layers of sand and clay of which the formation is made up are all earthy, and so soft that they can be dug with a spade.

The whole formation is composed of a series of strata of fire-clay, potters’ clay, brick-clay, sand, and lignite. The details of these, with their order, thickness, and qualities, will be given farther on in this report. The thickness of the series of strata is nearly three hundred and fifty feet. The strata ate generally parallel to each other, and are all inclined downwards towards the southeast with an average dip of about forty-five feet per mile. The direction or strike of the outcropping edges of the strata is south 46° west true bearing.

The geological age of this formation is determined entirely from its fossils, the series of earlier formations between this and the Azoic period being wanting here, and this lying directly upon the crystalline gneissic rocks. Fossil wood is abundant in many places, and the roots, leaves, and fruit of plants are sometimes found. Shells and remains of animals are rare.

Fossil leaves from the clay banks at Washington and Sayreville, from the clay pits at Burt’s Creek, from Mrs. Allen’s pit at South Amboy, and from the clay in the bluff bank of the Delaware two miles below Trenton were collected. These were submitted to the examination of Prof. Leo Lesquereux, of Columbus, Ohio, who makes a special study of vegetable paleontology, and is one of the most eminent authorities upon the subject. He reports as follows: "The specimens, very numerous, badly preserved, from Sayreville and other localities in the leaf-bed overlying the Woodbridge fire-clay bed, have, so far as they are determinable, the characters of the flora of the Dakota group, or of the lower Cretaceous, of Nebraska and, Kansas. This is lower Cretaceous for this country equivalent to a lower member of the upper Cretaceous of Europe. The species identical to both formations in New Jersey and Kansas are Magnolia Capellini, Heer; M. alternans, fleer; Persea Necrascensis, Lesqr.; Salix protoefolia, Lesqr.; two species of Proteoides; Glyptostrobus gracillimus, Lesqr.; Sequoia condita, Lesqr. I noted some other species as new, but they are not named or described; indeed, from the bad state of preservation of the leaves, it would not be possible to make a diagnosis without a comparative study of specimens with those I have on hand. Among others there are fragments of an Araliopsis, the basilar part of a leaf only, and we have from the Cretaceous of Kansas and now also from that of Colorado numerous species of the same genus.

"The flora of South Amboy, as collected from Mrs. Allen’s clay pit, totally differs in its character, as far represented by the few species known as, yet, from that at Sayreville.*** It has one, a single species, a Sterculia (new species), in common, and it is the only one. Most of the leaves of the lower Cretaceous stage have entire borders; on the contrary, those of this upper stage are serrate or denticulate on the borders. As said above, these upper Cretaceous leaves represent mostly new species referable to the genera Salix, Proteoides, Andromeda, Myrica, and perhaps a Prunus. There are many specimens of small cuneate flabellate leaflets, referable to a new genus of ferns; also leaves of Quercus, of the section Dryophyllum, and another narrow denticulate, apparently a Lomatia or a Myrica. The leaves of Salix are like those of S. protcefolia of the lower stage, but are covered with a coating of carbonaceous matter which renders their nervation obsolete. One of the leaves is referable to Andromeda, like A. parlatori, fleer.; another to Cinamomum Heeri, and two species of conifers, Sequoia rigida, Heer., and S. Reichenbachi, fleer., the leaves being shorter and narrower.

"Resuming:

1. Pettit’s clay bank near Washington, S.R.
    Sterculia, undetermined species.
    Rootlets of equisetum.
    Andromeda.
    Proteoides Daphnogenoides.
    Platanus Heerii, Lesqr.

2. Sayre & Fisher’s clay bank, at Sayreville.
    Glyptostrobus gracillimus, Lesqr.
    Sequvia condita, Lesqr.
    S. Smithsinia, Heer.
    S. Subulata, Heer.
    Araliopsis, undeterminable.
    Magnolia alternans, Heer.
    M. Capellini, Heer.
    Cinnamonium Heerii, Lesqr.
    Laurus,— species.
    Persea Nebrascensis, Lesqr.
    Dapbnophyllum?
    Salix protaefolia, Lesqr.
    Proteoides Daphnogenoides, Heer.
    P. undeterminable.
    Sterculia, species.

3. J.K. Brick’s clay bank, Burts’ Creek.
    Sassafras (Araliopsis).
    Seed of Conifer.
    Rootlets.
    A Sequoia with thick leaves.
    Sequoia Reichenbachi.

4. Mrs. Allan’s clay pit, South Amboy.
    Quercus, dentate leaves.
    (Dryophyllum.)
    Sterculia, same as above.
    Myrica or Lomatia.
    Salix protaefolia.
    Andromeda.
    Cinnamomum Heerii, Lesqr.
    Sequoia rigida, Heer.
    S. Reichenbachi, Heer.
    Leaves of a peculiar new kind of fern.

"These specimens are few and poor, and therefore the determinations are not positively ascertained."

Two specimens only of shells have been collected from the clays during the surveys. These are no very well preserved, but, they have been examined by Prof. W.M. Gabb, of Philadelphia, and by him determined to be the Cucullaea antrorsa, a species common in the green sand-marl bed. It is undoubtedly of the Cretaceous age.

Pebbles containing fossils are not uncommon in the gravel found in all parts of the clay district. Several small lots submitted to Prof. R.P. Whitfield, of the American Museum of Natural History, Central Part New York, were reported on as follows: "The fossil in the various lots are nearly all from the Upper Helderberg limestone group. Those from Martin’s Dock contain three species of Favosites, several fragments of cyathophylloid corals,a Michelina, also allied t Favosites, Atrypa reticularis, Strophodonta parva, and some other shells, fragmentary, also several specimen of an undescribed Stromatopora (spongoid).

"Those from Everett and Fish’s clay banks are mostly cherts and jaspers, and many, likely, from the Coniferous.

"The pebble with fish tooth is most likely Upper Helderberg. One other lot contained a curious pebble of sandstone, composed of a white matrix and rounded quartz, and on being broken open revealed a large fragment of Orthis hipparionyx, Vanuxem.

"Another lot reveals Atrypa reticularis, Spiriferae (species?), and several fragments of Devonian brachiopods and corals, and an impression of the dorsal side of ,a Gyroceras, or Cyrtoceras, very like C.----- ,Hall, from the Schoharie grit.

"There is no evidence of anything in the lot more recent age than the Hamilton, and that only on two fragments, the others being Upper Helderberg Oriskany, and perhaps some of the Favosites, Low Helderberg, possibly though not probably."

The source from whence the materials for the formation originated must be looked for to the southeast of the present strata. Though bordering upon and overlying the red shale and sandstone which lies to the northwest of it, there is not a fragment of these rocks to be found in any of these beds, nor any of their striking and characteristic red color to be perceived in them. On the contrary, the materials of these beds are white, gray, or blackish, and if at all tinged with the reddish color of oxide of iron, it is a yellowish red, and not a purplish red, like the red shale and red sandstone. The appearances all indicate that they have originated from the materials of disintegrated and partially decomposed feldspathic granite or gneiss. In some places these products of disintegration have been sorted by water, the fine particles of clay deposited by themselves to make the present clay-beds, in others the quartz has been deposited as sand in beds by itself, and in still other places the finest of the sands, with a little mica almost in powder, has been deposited to make the so-called kaolin beds. In other beds the materials are deposited in their original mixed condition, clay and quartz together constituting the so-called feldspar beds of this district.

There does not appear to have been any violent or irregular movements since the deposit of the clay-beds which has disturbed or distorted them. But there must have been high ground to the southeast and outside the present line of sea-coast, from which the materials for the clay and sand could have been washed and deposited on the lower ground, upon which they still lie. And this high ground, besides what wore away to make these beds, must have gradually settled down till, it was hidden beneath the ocean, and the beds of the clay formation have risen along their northwestern border till they were above the sea-level, and till the beds had so altered their inclination as to slope down towards the southeast instead of towards the northwest, as they did when first deposited.

THICKNESS OF THE FORMATION.— The plastic clay formation here described consists of the following members, or sub-divisions, beginning at the top, viz.: 

The columnar section here given shows the position and relative thickness of the several members of the clay formation. These several members of the plastic clay formation are not equally well defined and clearly marked by characteristic features, neither do they always appear of uniform thickness, corresponding to the figures as stated in the above general section and order of superposition. The series here given represents the succession of the several subdivisions or beds, and their average thickness, as observed in localities where they appear fully developed, and have not been subsequently eroded or otherwise diminished in thickness through the action of outside agencies. The order of succession or superposition is made up from a survey of the whole.

* From "Report on the Clay Deposits of Woodbridge, South Amboy and other places in New Jersey," etc., by George H. Cook, State geologist, and John C. Smock, assistant geologist.

** Geologically, this clay district extends over a part of the south end of Staten Island, and probably to Long Island also.

*** It is comparable to an upper Cretaceous bed of Southwest Colorado.
     See Ann. Rep. of Dr. F.V. Hayden, 1874, p. 360.