~pg 16~
The amount of waste is so large, therefore, that quarries cannot be profitably worked in this whole division.  the third portion of the series, the Hill quarries have often lower limits-the beds in which the solid rock has risen again to as high a proportion as one foot in five or six feet of ascent.  From this point upward to the completion of the group, there is no such predominance of shales as is found below, though in the lower parts of the Lebanon beds shales still constitute more than one-half of the whole thickness.

It is seen from analyses made that a notable quantity of alkalies and phosphates, sometimes at least, occurs in the composition of the shales.  It is upon these substances that the fertility of soils in great measure depends; and as they are in this case properly distributed through the sand and clay that make the bulk of the shales, it is in no way surprising to find very fruitiful soils forming from the weathering of these beds.  The most noteworthy fact in this connection is the rapidity with which they are converted into soils.  Most of the rocky shales of the State require a long course of progressive improvement before they can be justly termed soils.  Their elements are slowly oxidized and disintegrated, and vegetable matters slowly added.  The exposure of a single season, however, suffices to cover the Cincinnati shales with a varied vegetation.  All of our ordinary forest trees, when opportunity is furnished for the distribution of their seeds, establish themselves promptly upon the shales.  The black locust seems especially well adapted to such situations.  There is no other use to which the steep slopes of the Cincinnati hills can be turned that would subserve as many interests as planting them with black locust would do.

Dr. LOCKE called attention to a particularly feature of the Blue Limestone beds, viz, a waved structure of the solid limestone, somewhat analogous in form ot the wave-lines and ripple-marks of the higher series of the State.  This peculiar structure was noticed by him in the upper beds of the formation, but it is even a more striking characteristic of the rock in its lower beds, as shown in the river quarries of Cincinnati, or in the lowermost hundred feet that are there exposed.

The rocks exhibiting this structure at the point named are the most compact beds of the fossiliferous limestone.  The bottom of the waved layer is generally even, and beneath it is always found and even bed of shale.  The upper surface is diversified, as its name suggests, with ridges and furrows.  The interval between the ridges varies, but in many instances it is about four feet.  The greatest thickness of the ridge is six or seven inches, while the stone is reduced to one or two inches at the bottom of the furrow, and sometimes it entirely disappears.  The waved layers are overlain by shale in every instance.  They are often continuous for a considerable extent, and in such cases the axes of the ridges and furrows have a uniform direction.  This direction is a little south of east in the vicinity of Cincinnati, but in various directions.

Dr. LOCKE's explanation of these facts, involving a fluid state of the carbonate of lime and sheets of shale falling in a "vertical strata" through deep seas, seems entirely inadmissible.

The only other explanation thus far proffered is that suggested by the name, viz, that the floor of the Cincinnati sea was acted on from time to time by waves or similar movements of the ocean waters.  In opposition to this view it may be said: First, that there are many reasons for believing that the Cincinnati rocks grew upon the floor of a deep sea, far below the action of the surface waves; and second, that the fact of the limestone layers alone being this shaped is sufficient to set aside the explanation.  If these inequalities of surface are due to wave-action of any sort, it is impossible ot see why the action should be limited to the firmest limestone beds of the series, while the soft shales, which could easily register any movement of the waters, never exhibit the slightest indications of such agencies.

While both of these modes of accounting for the facts are rejected as entirely unsatisfactory, nothing in the way of explanation will be offered here, save the suggestion that the facts seem to point to concretionary action as the force to which we must look.
 

The Economical Products

of the Cincinnati group are limited to building stone, lime, brick and pottery clays, and cement; and of these none but the first two have, at present, any great importance.  The series yields everywhere abundant supplies of stone, suitable in every respect for building purposes.  The advantages that the city of Cincinnati reaps from the quarries that surround it, are immense.  While blue limestone has been used as a building stone from the first settlement of the country it has hitherto enjoyed the reputation of being serviceable rather than beautiful; but within the past few years it has been so treated by combination with other building stones as to produce very fine architectural effects.  Numerous exhibitions of this skillful use of the blue limestone can be seen in the recent buildings of the city and suburbs of Cincinnati.

The analysis of the stone shows it to contain ninety or more percent of carbonate of lime.  From this it will be concluded that it can be burned into a lime of a good degree of purity and strength.  When water-washed pebbles from gravel banks or river beds are used, the product is excellent; but the quarry stone always carried with it so much of the interstratified shale as to darken the lime and so reduce its value for plastering.  For this last use the mild and white magnesian limes derived from the Upper Silurian formations that surround Cincinnati, are the only varieties that are at present approved.  The native supply can, however, be furnished much cheaper at but little more than half the cost, indeed, of Springfield lime; and as it makes a strong cement, the shales that adhere to the stone possible adding an hydraulic quality, it is generally used in laying foundations of all sorts.

The shales are sometimes resorted to for the manufacture of brick, tile, and pottery ware.  The instances are, however, rare, and are confined to the uppermost beds of

The occurrence of concretions in the shales of the Point Pleasants beds and in the lowest strata of the division found at Cincinnati, has already been noticed.  The analysis of specimens from the river quarries suggests hydraulic cement, and they are in fact found to possess a high degree of hydraulic energy.   The supply of these concretions depends upon the extent of the quarrying, but at the present rate several hundred tons are thrown out each year, and as the concretions prove nearly enough uniform in composition, they can certainly be turned to good, economical account in the manufacture of a fine quality of cement.  The famous Roman cement of England is obtained from similar concretions, which are generally gathered on the shore after storms and high tides,  though sometimes obtained by digging.  All of the river quarried from Point Pleasant to Lawrenceburgh, Indiana, yield these concretions-the lowermost beds of all most abundantly.  It may be added that the limestones enclosing the concretions are siliceous enough in composition to transfer them to the best of cements.

The Cincinnati section exhausts the scale of the county, the upper division of the blue limestone, as before stated, having never been found within its limits.  The River Quarry beds do not constitute a marked feature, in any respect, of the geology of the county.  There are but comparatively few points where these strata are exposed.  A moderate amount of building stone of superior quality is taken from the Covington quarries, opposite Cincinnati.  But little of the stone in this portion of the series can be burned into lime, but the concretions so abundant in many of the beds, as just hinted, constitute an hydraulic lime of great energy.

The second element of the Cincinnati section-the Middle or Eden shales-is as much more prominent than the first in the county as its greater extent in the vertical scale would lead us to infer.  It is, however, mainly found in the slopes of the hills, as it is not firm enough in structure to resist denuding agencies, when unprotected by the higher series.  Very few products of economical value, as we have seen, are derived from this part of the scale.  Indeed, its relations to economical interests are mainly in the way of disadvantages to be overcome. These disadvantages result directly from the nature of the materials of which these beds are composed.  It will be remembered that in the two hundred and fifty feet now under consideration, not more than one foot in ten is limestone; the remainder being soft shales, or soapstones, as they are variously designated.  These shales have scarcely tenacity enough to hold their place in steep descents when acted on by water and ice; still less, when they have been removed from their original beds, can they be made to cohere; and they thus form treacherous foundations for buildings erected on them of for roadways constructed in them.

The city of Cincinnati, in many of its building sites, streets and approaches, encounters these disadvantages, which can only be overcome by increased outlay  in the way of foundations.  These facts are most clearly shown in the approaches to the city from the east by the Ohio valley, frequent slides occurring along the steep slopes of shale in which streets and dwellings are involved.  Gilbert avenue, in process of construction through Eden park, especially suffered from its geological formation, and required a large expenditure to give it stability along this line.

Nearly all the smaller streams that are bedded in these shales show contortions and flexures of their strata that have resulted from the slipping of the higher beds into the valleys.

The third division, viz., of the Hill Quarry series, which makes the upland of the county, is by far the most important of the three, in the area it covers and the products it furnishes.  The summits of the insulated masses already named belong to this division, and constitute about three-fourths of the surface of the county.  Most of the quarry stone of the county is also derived from this source.  The Cincinnati quarries have thus far been vastly more important than those of any other district; but as the hills within and adjoining the city limits are being occupied for building sites, it will result that railroad transportation will be invoked; and when it comes to this, the more desirable building stone of the different formations from adjoining counties will come into competition and be more largely used.

It may be noticed here that it is chiefly due to the fact that so large an amount of quarrying has been done about Cincinnati, that this particular locality has become the classic ground in the way of fossils that it now is.  The numerous and ample exposures gave tot he earlier collectors unexampled opportunities-opportunities which are not likely to be repeated.  Many of the most interesting localities of twenty to twenty-five years ago are now covered by permanent buildings, and every year diminishes the available areas.  The waste of the hill quarries furnishes, however, by far the larger proportion of the admirable fossils in the vicinity of cincinnati.  Scarcely any exposure of it in the county has failed to yield choice forms of the various and rarer groups.
 

DRIFTS DEPOSITS, OR SURFACE GEOLOGY

The drift formations of the county are mainly divided into two groups, corresponding to the main topographical features of the county already indicated, viz.:
        First-The drift deposits of the highlands and slopes.
        Second-The low land, or valley drift beds.

I.-Drift deposits cover the highland of Hamilton county, with but very limited exceptions.   Towards the southern boundary these beds are light, measuring but a few feet (four to ten) in thickness; and, as already intimated, areas are occasionally found from which these deposits are altogether absent, the shallow coating of soil found in such areas being native or referable to the decomposition of the limestone that has been bedded here.

There is a good degree of uniformity among these

The average thickness of these upland drift beds falls below twenty feet, but occasionally heavier sections are found.  In the northern part of Sycamore township, in the vicinity of White Oak school-house, a high drift ridge occurs in which twenty feet of surface clays are underlain with a deposit of fine yellow moulding sand.  This stratum, when filled with water, is a quicksand, and renders wells impossible, or at least very difficult to secure.  But little clean gravel occurs in the uplands of the county, and boulders also are infrequent.

The yellow surface clays sometimes overlie a few feet of tough blue boulder clay, filled with scratched and striated pebbles, apparently the product of the melting glacial sheet.  This is not, however, by any means a constant element in the section.

In short, the upland drift of this county is not as varied and interesting as that of the regions immediately to the northward, or even to the eastward.  The slopes show the same characters in their drift beds that have already been described, except that the deposits are generally heavier.

II.-The second division, or the lowland drift-beds of the county are in their characteristic formations of much later date than the deposits already discussed.  These deposits can be classified in their superficial aspects, under the principal divisions, viz: (a) The bottom lands; (b) the terraces or second bottoms.

These divisions are distinguished from each other, not only by their different elevations but also by the different materials of which they are composed, the terraces being largely composed of gravel, with occasional beds of sand and clay, while the bottom lands contain, in all cases, a greater proportion of fine materials.

Of the upland drift no general of typical section was given, for the reason that, aside from the monotonous deposits of yellow clay, there is no uniformity in the order in which the different formations occur; but in the case of the divisions now under consideration, it is possible to represent in a single section the more important facts that are to be observed.  The deposits of the Ohio valley, it will be remembered, are to be especially considered in this report.

A section is here appended, taken at Lawrenceburgh, Indiana, which gives the general structure of the Ohio bottom lands more clearly than any exposure met with, strictly within the limits of the county.  beginning at low-water, we find the deposits that make up the river bank arranged in the following order (ascending):

            6. Brick clay, covered with one to two feet of soil.................................6 feet
            5. Land, gravel, and loam....................................................................30 feet
            4. Ochreous sand...............................................................................1 1/2 feet
            3. Carbonaceous clay, an ancient soil or forest bed...............................7 feet
            2. Ochreous sand...............................................................................1/2 foot
            1. Clean gravel..................................................................................6 feet
                        Total.....................................................................................51 feet

The elements of this section will be noted in their order.  The first of them, six feet of gravel, is perhaps the least constant of the series, being sometimes substituted by some of the clays of the drift.  The gravel of the Ohio differs from that of the Miamis in being largely composed of sandstone pebbles instead of limestone.  It is, consequently, less durable than the river or bank gravel of the Miami districts, and this fact, taken in connection with the difficulty of access, withholds it generally from applications to road-making.

The second, third, and fourth elements need to be taken together, as they are closely connected in their history.  The point to be noted in regard to them is the constant occurrence of carbonaceous clay between the seams of ochreous gravel.  The clay is quite heavily charge with vegetable matter, much of it in such a state of preservation that it can be readily identified, and often portions again intermingled in a fine state of subdivision with the substance of the clay.  The minutest roots of trees-some of the latter still in place-twigs and branches, layers of leaves, ripened fruits, grapes, and sedges, are all clearly distinguishable.  Several of the species of trees can be determined, some by their wood, others by their leaves and fruits.  Among them may be named the sycamore, the beech, the shellbark hickory, the buckeye, and the red cedar.  A cucurbitaceous plant, probably the wild balsam apple, is also shown to have been abundant by its seeds, which are preserved in the clay.

The leaves frequently occur in layers several inches thick, and are very like the accumulations that are now left in eddies of the river by freshets or floods.  The deposits of the river at present always have an elevation of at least twenty feet and sometimes even of forty feet above the bed now under review.

The constant occurrence of vivianite or phosphate of iron in this deposit is to be noticed.  Its' presence indeed is an invariable characteristic.  The mineral is usually found in small grains, but sometimes it replaces twigs and leaves and other vegetable growths.  The quantity in some portions of the beds is considerable, amounting, sometimes, to two or three per cent of the whole deposit.  In such cases it imparts its color to the mass, and this justifies the name by which it is known, "blue earth."

Several apparently trustworthy accounts have been received of the discovery of the bones and teeth of the mastodon and mammoth in this deposit; but these and all other mammalian remains are of very rare occurrence.  It is possible that the "chips" and "axe-marked" stumps reported at various points in excavations in the drift beds, attest the former presence here of the gigantic beaver now exticnt=castoroides Ohioensis.  It was certainly a tenant of the State during the general period to which this old forest bed must be referred.  That its work upon trees might easily be mistaken for axe marks, will need no proof to any one acquainted with the work of the existing species of beaver.

In a few instances, land and fresh water shells have been found in the clay, sometimes in quantity enough to convert the clay into a shell marl.

This stratum is shown at all points along the valley in which bottom lands occur.  Its elevation above low-water varies from five to twenty feet.  It is generally covered superficially with the waste of the overlying banks; but even in such cases it reveals its presence by the long lines of willows and other vegetable growths that establish themselves upon its outcrop.  Two things conspire to adapt it especially to the growth of vegetation.  In the first place, it is an impervious stratum, and turns out the water that descends throughout the overlying loams and sandy clays, thus giving to willows and other plants of like requirements a constant supply of moisture; and secondly, this stratum, as has been already intimated, is in reality an ancient soil, having been carried at an earlier day through the processes of amelioration by which beds of sand and clay are fitted to support vegetable growths.

There are, however, many places where the force of the current in high water uncovers these beds, and where consequently good sections are always offered.  Excellent disclosures of them are found at New Richmond, Clermont county, and also at Point Pleasant, on the Kentucky shore.  The spring flood of 1872 furnished an unsurpassed exhibition of this formation at the mouth of the Little Miami river.  Rafts of tree trunks are shown at all of these points, though the wood generally perishes very quickly when exposed to the air.

That this very interesting stratum so long escaped observation is probably due to the fact that it could so easily be referred to the agencies that are now at work in the valley.  When the trunks of trees and layers of leaves belonging to it have been noticed in the banks of the river, it has naturally enough been supposed that they are the deposits of earlier floods, agreeing as they do with the materials transported by the floods of our own time.  But in describing the Lawrenceburgh section, now under consideration, as the general section of the Ohio valley deposits, it has already been shown, at least by implication, that this explanation in inadmissible.  The extension of this sheet of carbonaceous clay under all the various drift deposits of the valley, as is shown by very numerous natural and artificial sections, proves that it is of earlier date than those overlying deposits, and the character of this stratum shows that it has a very different history from that which these higher deposits record.

It is, perhaps, still too early to write out this history in its minuter features, but the facts already given show us that we have in this sheet of blackened clay the bottom lands of the Ohio at an earlier day, and, indeed, under very different conditions from those that now prevail.  The river then ran in a channel lower by forty feet, at least, than that which it now holds, and the great valley was then empty of the immense accumulations of sand, clay, loam, and gravel, which constitute its bottom lands and terraces to-day.

The various vegetable growths with which this stratum is filled, are to be regarded as largely the production of the sold on which they are now found.  There is no other satisfactory mode of accounting for the particular kinds and enormous amount of vegetable matter traced here.

The ochre seams above and below this ancient soil seem to point to marshy conditions that were brought in with the changing levels of the valley.  Of the two, the upper seam is the more constant.

In the Lawrenceburgh section we find thirty-five feet (thirty to fifty in the general section) of sands, gravels, clays and loams, which constitute the Ohio bottoms, as the term is generally used.  There is no fixed order in the alternation of these materials, except that the surface portions have, for a few feet in depth, a tolerably uniform character.  The soil of the bottom lands is quite homogeneous in constitution, and has obviously been formed by the subjection to atmospheric agencies of just such material as it now covers.  Beneath the soil, and extending to a depth of about fifteen feet, beds of yellow clay occur.  The proportions of sand mixed with the clay vary somewhat, increasing towards the lower limit named, and below this the beds consist rather of sand than clay.  The beds of clay above named furnish an excellent material for brickmaking.  The supply of the Cincinnati market is almost entirely derived from this horizon.  The great depth of these brick clays, and their entire freedom from pebbles, render a very economical manufacture of brick possible.

Below this limit, sand and gravel and streaks of loam are met, without regularity of arrangement.  Of the fifteen to twenty feet intervening between the bottom of the brick clays and the summit of the buried soil, the larger part consists of gravel.  The gravel of this horizon is seldom clean, like that described at the level of low-water, but consists of large-sized sandstone pebbles, four to six inches in diameter, mingles with finer materials.

An equivalent of these beds, but of local occurrence, is the fine-grained clay described in the geological reports as "Springfield clay." It never occurs in extensive sheets, but is quite limited in vertical and horizontal extent.  The heaviest accumulation of it observed in Hamilton county is in the city of Cincinnati, on East Pearl street, above Pike.  It has a thickness there of more than thirty feet, as has been ascertained in the excavations for the foundations of buildings.  It has been turned to account in its different exposures for different purposed-at Miamisburgh, for the manufacture of paint; at Springfield, for the manufacture of "Milwaukee  brick," the clay being rich in lime and poor in oxide, and thus

The gravel terraces occupy a higher level than the formations already described.  The terrace on which Cincinnati stands, may be taken as fair example of them all.   Its altitude above low-water varies from one hundred to one hundred and twenty feet, the average elevation being one hundred and eight feet.  It is composed of distinctly stratified gravel and sand of varying degrees of fineness and purity.  The gravel stones are all water-worn.  In weight they seldom reach ten pounds.  The upper tributaries of the Ohio supply the materials in part, but a much larger proportion in the vicinity of Cincinnati is derived from the limestone rocks of western Ohio and the crystalline beds of Canada.  The proportion here to be noted among the smaller-sized pebbles is, of ten feet, five of Upper Silurian and Devonian limestones, three of Lower Silurian, least worn, one foot of granitic, and one of sandstones, etc, of the Upper Ohio.  Occasional seams of clay loam occur, but seldom of extent or tenacity enough to constitute reliable water-bearers.  Less frequently met, but still constituting a noteworthy feature of the gravel terraces, are seams of bituminous coal, in small water-worn fragments.

The terraces overlie, as will be seen, the formation previously described.  Few sections are carried deep enough to reveal the lower beds, but the leaves and wood of the buried soil are occasionally met at considerable depth, and usually, on this account, they attract attention.  The following general order of materials will be observed in passing from the surface of the terrace to low-water.

                                                        Soil.............................................................2-5 feet
                                                        Gravel and sand, with seams of loam............-4060 feet
                                                        Brick clay, with sand and loam.....................20-30 feet
                                                        Buried soil, with trees, leaves, etc.................5-10 feet
                                                        Gravel and clay...........................................5-10 feet

                                                                                                                          72.115 feet

The leading facts in the structure of the terraces show that their history is not to be explained by the present conditions of the continent.  They must have been formed under water at a time when the face of the country held a lower level than it does, by one hundred or more feet.  They thus bear direct testimony to two of the most surprising conclusions which the study of the Drift period has furnished to us, viz: That the continent sank, during the latter stages of this period, considerably below its present level, and that it was afterwards re-elevated.

There is one other line of facts in connection with the drift beds of the county that must not be omitted here.  It is the great depth which some of these deposits have been found to hold below the present drainage of the country.  The series of facts obtained by Timothy KIRBY, esq., in boring a deep well in Mill Creek valley, at Cumminsville, now within the corporate limits of Cincinnati, proves very interesting in this as well as in other respects.  Beginning at an elevation of ninety feet above low-water of the Ohio, a succession of drift deposits was penetrated until a depth of sixty feet below low-water was reached, the bedded rock being first struck at a depth of one hundred and fifty-one feet below the point of beginning.  The deposits included, in descending order, twelve feet of soil and brick clay, four of sand, thirty-four of blue clay with gravel, nineteen of gravel, three of coarse sand, eleven of sand with fragments of bituminous coal, nine of blue clay with gravel (at the bottom of this the level of low-water in the Ohio was reached), sixteen of blue clay and fine sand and sprinkled with coal, and forty-three of sand, water-worn gravel, and blue clay, with occasional fragments of bituminous coal, below which, at the depth of one hundred and fifty-one feet from the surface, were the shales of the Blue Limestone group.  Several remarkable facts are to be observed in this section, the most striking of which is the great depth to which the excavation of Mill Creek valley was formerly carried.  The bed of the stream that occupies the valley to-day is at a higher level by one hundred and twenty feet than that of the ancient channel.  It is easy to see that this erosion could not have been effected under existing conditions.  It can only be explained by a higher altitude of the continent, and is thus referred to the opening division of the glacial period.  It has not been demonstrated that continuous channels exist at this great depth; but the rocky barriers that fringe the streams do not at best disprove this theory, as there is always room for a deeper channel on one side or the other of the great valleys.

Another interesting fact is the occurrence of water-worn fragments of bituminous coal, quite similar to those found in the terraces already noticed.  They occur at various depths, the lowest at one hundred and fifty feet below the surface and the highest at eighty feet below.  These facts, so far as known, stand by themselves, and no explanation is proposed.  It is hard to see how the waste of Ohio coal-fields should find its way in quantity into Mill Creek valley, and there is certainly no other obvious source of supply.

The well from which these facts were obtained was carried to a depth of five hundred and forty-one feet below the surface.  Analysis of the chips and borings brought up and preserved reveal the character of the strata underlying Ohio to a depth greater by about four hundred feet than any other rocks exposed within the limits of the State.  The shales of the blue limestone series appear to continue to a depth of four hundred feet from the point of beginning.

Carburetted hydrogen gas escaped from the well in considerable quantity from a depth of two hundred and eighty feet downwards, but no large accumulations of petroleum compounds were indicated.