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EXTENT OF THE WHEAT-REGION.
From the lake to the beginning of the Marcellus shale -No. 6 on this section, at a height of 216 feet, the level of Seneca Lake—is about thirty miles. The rise of the country, therefore, is very gradual; indeed, it is comparatively level after the first ascent over the Niagara limestone till we reach the Marcellus shale. Beyond this shale it rises more rapidly; and at Ovid there is a bold escarpment where the two bands of limestone occur. In other parts of the country there are also bolder escarpments along the out-crop of the Niagara and Helderberg limestones than the section shows, forming marked and successive steps as we advance into the interior.
From the lake to the Marcellus shale is the proper wheat-district, though in some places it extends to the Genesee slate, and may ultimately, under a better system of culture, be generally extended thus far. But the rapid rise of the land, by altering the climate, will always make this higher region less propitious to vegetation, supposing the soil as good as those of the Onondaga and more northern formations.
No. 1. The Medina sandstone consists of layers of brownish sandstone intermixed with shales. It presents an interesting illustration of a fact of much importance in agricultural geology, that the same formation at different parts of its extent may produce soils very different in their nature. Towards the east, the sandstone greatly predominates, forming sandy soils comparatively poor in agricultural value. But towards the west, the shaley or clay beds increase in number or thickness; so that sandy loams, and finally clay loams, and excellent wheat-soils, are produced from it.
No. 2. The Clinton group consists of green and blue shales and limestones, the admixture of the fragments of which forms an excellent wheat-soil.
No. 3. The Niagara formation consists of the soft shales below, and of the thick impure limestone beds above,
SOILS OF THE NIAGARA ROCKS.
which give their character to the Niagara Falls, and to the outline of the landscape. The sbale alone forms stiff clays, which, from the sloping nature of the surface, are generally dry and susceptible of culture; while the limestone alone, where it is sufficiently crumbled, produces a surface adapted for wheat or Indian corn. But where, from the washing away of the Clinton beds, which are only 60 or 80 feet in thickness, the Niagara shales come in contact with, or are mixed with the debris of the Medina sandstone, soils are produced which are of “ unequalled fertility"—illustrating another important principle, of which we have many examples in England, that, at the junction of beds of different kinds of rock, the soils are often much superior to those which are produced by the fragments of either rock alone.
No. 4. The Onondaga salt-group consists, as I have already said, of red and green shales below, succeeded by porous limestones, and these by beds of shale, including irregular but larger deposits of gypsum, the whole surmounted by other green shales or thin beds of impure light-coloured limestone, containing much magnesia. Calcareous matter abounds through the whole of this fertile formation-and generally the soils are rich, free, and easily worked.
No. 5. The Helderberg limestones and sandstones, where the surface is hard and rocky, are often covered with a thin soil of less value ; but where the soil is deep, it is of excellent quality. Here, however, as a wheatregion, the natural quality of the surface begins to fall off.
No. 6. The Marcellus shale is thin, varying from a few feet to 60 or 80, so that its effect on the surface is seen chiefly by its improving the Helderberg series at the point of junction, and by forming occasional stripes and patches of stiff clay.
No. 7. The Hamilton group, when alone, forms stiff dark-coloured clays, which are less rich in calcareous
PORTAGE AND CHEMUNG SOILS.
matter than the Onondaga soils, and therefore less free and more difficult and expensive to work, but capable of producing excellent wheat. A large portion of the celebrated Genesee Valley rests upon this formation; but its natural soil is there covered or modified by the drifted fragments of the Niagara and other more northerly limestones. This group is of great thickness, and forms an extensive belt of country, the soils of which in some places are rich in lime, and are submitted to arable culture. They are everywhere difficult to keep clean, however, and are especially infected with the pigeon-weed (Lithospermum.) They are, for the most part, therefore—like our own stiff clays of the lias and other formations—left to perpetual grass, which they produce of excellent quality. Here, therefore, the grazing and dairy country of western New York commences.
No. 8. The black Genesee slate is too thin to form an important agricultural feature in the country. It crumbles more slowly than the Hamilton shale, but where it mixes with the thin limestones and calcareous shales beneath it, good soils are produced.
No. 9. The Portage and Chemung groups consist of alternations of shales, poor in lime below, with flagstones and massive sandstones. They extend to the borders of Pennsylvania, where they reach the height of 1000 feet above Lake Ontario. The district occupied by these groups presents a complete contrast to the wheat-region. When first cleared, it produces crops of wheat; but after the first crops—as is the case in many parts of New Brunswick, which rest upon similar rocks -wheat-becomes uncertain, and spring grain only can be sown. It is therefore poorer, less cleared and cultivated, and possesses a poorer race of cultivators. The farmers devote their attention chiefly to the rearing of stock, and to the dairy husbandry.
To teach a man the close relation of natural agricul
INFLUENCE OF DRIFT.
er interewheat-ended t
tural capabilities and early agricultural prosperity with the nature of the rocks of a country, it is only necessary to ascend from the valley of the Onondaga shales to the hills of the Portage sandstones.
But another interesting and instructive feature presents itself in this wheat-growing belt. The waters which in former times descended this region came from the north, and have drifted the materials of the more northerly over the edges of the more southernly rocks. Thus the materials of the Medina sandstone are made to overlap the Clinton and Niagara clays, and so to mingle with, lighten, and improve the soils formed from them. The Niagara shale, again, has overlapped the overlying Niagara limestone, mixed with it, and deepened its naturally thin and more slowly crumbling debris. So the various soft beds of the Onondaga salt-group have been intermingled, and a comparatively low, level, and undulating surface been given to the whole. The abundant materials derived from this easily crumbling group, again, have been spread over the Helderberg limestones, and the fragments of these over the Marcellus and Hamilton shales, adding to the calcareous matter of these latter rocks, and thus widening the belt of wheat-growing country beyond its natural limits.
This widening is especially visible along the north and south valleys, which penetrate far into the Hamilton and Portage groups of rocks, and into which the fragments of the Onondaga group were naturally carried by the rushing water. Up the valley of the Genesee River, and into the outlets of the Seneca and Cayuga lakes, this drift has penetrated farthest; and to its presence is due the peculiar agricultural excellence for which the soils of these localities are known, and which the rocks on which they rest could not alone have imparted to them.
The first freshness of nearly all these naturally fertile
SALT-SPRINGS OF THIS DISTRICT.
lands, which have been long under cultivation, has been rubbed off them by ignorant and improvident culture; but skill, the child of greater knowledge, can restore them again to great productiveness. How far it will pay to improve even this country, for the growth of wheat-as our best English and Scotch farmers would like to improve it—while the still uncleared lands of the north-west are competitors in the wheat-market, I do not possess sufficient knowledge of local circumstances to enable me to decide.
With Mr Geddes I afterwards visited the salt-works for which this district is so celebrated, and to which the city of Syracuse is so much indebted for its rapid prosperity.
Salt-springs occur over the whole of this belt of country, from the Medina sandstone to the Portage group inclusive; and salt has been, or still is, more or less extensively manufactured from them. But they are most abundant, and yield most copious supplies of water, in the Onondaga salt-group, which derives its name from them. In this group they are generally richer also in saline matter, and yield a purer salt.
As in so many other localities, the gypsum appears to be connected in its mode of deposition with that of mineral salt. There occurs, indeed, in this localityupon Mr Geddes's farm among other places—a very interesting proof of the close connection of these two mineral deposits. In the green shale-beds are found numerous pseudo-morphous masses, sometimes as much as six or eight inches in diameter, which appear to be casts of the interior of large hollow crystals of common salt, such as are formed, of a smaller size, on the surface of salt-pans, or of bodies of salt-water which are evaporated in the open air. Such hopper-shaped casts, as they are called, were very numerous in the locality in which I saw them, throughout the entire body