TABULAR VIEW OF THE ROCKS OF NEW YORK, ARRANGED IN SYSTEMS, GROUPS AND FORMATIONS.

There are in the state two tracts of primary and unstratified rocks. The first is nearly circular in form, and occupies the counties of Essex, Warren and Hamilton, and portions of Saratoga, Fulton, Herkimer, Oneida, Lewis, Jefferson, St. Lawrence, Franklin and Clinton. The Black river forms its southwestern boundary, from Wilna, in Jefferson, to Remsen, in Oneida county.

The second is in the southeastern part of the state, of a somewhat triangular form, and comprises Putnam and Westchester, together with the larger part of New York, and part of Rockland, Orange and Dutchess counties.

These two sections together occupy nearly one third of the state.

They contain extensive and valuable mines of iron, lead and plumbago, both in the northeastern and southeastern portions of the state. Their surface is generally broken and elevated, towering up to the height of more than a mile above tide water, in the Adirondack group, and attaining a considerable, though less lofty altitude in the beetling cliffs which overlook the waters of the Hudson.

The soil is less arable and fertile than in the lands of the limestone formations, but is covered, except in the older counties, with a gigantic growth of oak, pine and hemlock timber.

The gneiss of this system furnishes a fine building material, and under the name of granite, is abundantly quarried for that purpose. The serpentine, primitive limestone, and steatite, are also largely quarried for the purposes of the arts.

These rocks abound in minerals of great interest to the mineralogist. Garnet, beryl, chrysoberyl, pyroxene, sphene, tourmaline, apatite, colophonite, scapolite, Labradorite, epidote, &c. &c.

Geologists differ in opinion, on the question, whether the Taghkanic, or Taconic system should be ranked with the Primary, or the Transition system. It is composed of brown sandstone, limestone and green shales, or slaty rocks. It contains seme minerals, and furnishes a fine limestone for building, but has few, or no fossils. The soil which overlays this system is generally good, and often highly fertile.

Its range is quite extensive, although frequently of no great width. It comprises nearly the whole of the counties of Washington, Rensselaer and Columbia, part of Dutchess, Ulster, Greene, Albany and Saratoga, and trending westward occupies a narrow tract in Schenectady, Montgomery, Herkimer and Oneida, and expands more widely in Oswego and Jefferson counties.

We next come to the New York system, as it has been appropriately named, comprising, according to the table, four distinct groups. We commence with the lowest of these, the Champlain Group. The constituents of this group are various kinds of sandstone and limestone, slate, conglomerate, and a peculiar stone, compounded of lime and sandstone, and hence called calciferous (or limebearing) sandrock.

Of these the Potsdam sandstone furnishes a beautiful and durable building material, and is also used in the manufacture of glass, and the preparation of sand paper. The Trenton and birdseye* limestones are used for the purposes of the arts. The Lorraine shales, and the Utica slate are employed for roofing, and to some extent for writing slates. The grey sandstone and conglomerate furnish stone suitable for grindstones.

The rocks of this group, and particularly the limestones and slates, abound in fossils of the earlier periods; encrinites, trilobites and numerous others, unlike any of the crustaceous animals now in exist

ence.

The soil, throughout the territory occupied by this group, is generally good, and much of it is highly fertile, being constantly enriched by the decomposition of the limestone, slate and sandstone, which is

• This limestone receives its name from the ab indance of encrinites which it contains, which give it, when polished, an appearance somewhat resembling birdseye maple.

effected by the combined action of air and water. The group occupies a very considerable, but irregular territory. It appears occasionally in small beds, then dips beneath the surface, and again appears, as the surface rock, over an extensive tract. In the forms of Potsdam sandstone, calciferous sandrock, birdseye and Trenton limestone, and Utica slate, it bounds the great primary region of the northeast in every direction, varying in width from two to fifty miles. It also makes its appearance in narrow beds on either side of the Hudson.

The Ontario Group, which comes next in order, consists of three distinct portions; the lowest a marly sandstone, generally soft, and either red, green, brown, or variegated,-decomposing rapidly, when exposed to the atmosphere, and denominated Medina sandstone ; next, a series of soft, green, slaty rocks, also easily decomposed, and overlaid by clayey and flinty limestones, alternating with each other, and finally terminating in the limestone over which the Niagara pours its resistless cataract; and lastly a group of limestones, containing gypsum or plaster of Paris, water lime and salt, known as the Onondaga salt group;

This group, considered with reference to practical purposes, is the most valuable of the transition system in the state. It includes the salt springs in Salina and its vicinity, and at Montezuma, which yield so large an amount of revenue to the state; the gypsum beds, which furnish such inexhaustible resources for the fertilization of the soil, as well as for the various purposes of the arts, to which this valuable mineral is applied; and the water lime, called, after its preparation, hydraulic cement, a material indispensable to the proper construction of canals, aqueducts, cisterns, and other masonry exposed to the action of water, and one which has proved of the greatest service in the construction of the public works of the state.

The fossils of this group are numerous and interesting. Shells of bivalve molluscous animals, corallines and madre pores, together with unequivocal traces of vegetable existence, mark this era.

Its minerals are not numerous. The clayey limestones contain iron ore; fluor spar and selenite appear occasionally, and sulphur springs gush up from different sections. Its soil is of unsurpassed and perpetual fertility, being constantly enriched by the slowly decomposing lime and gypsum. It is the granary of the state, and before the wide prairies of the west waved with the golden grain, it supplied nearly the whole country with bread-stuffs. The oak, beech, maple, elm, butternut, hickory and black walnut, are the principal forest trees. The Ontario group commences at the southwestern extremity of Lake Ontario in Canada, and extends eastward with a medium breadth of twenty miles to its termination in Montgomery county.

The Helderberg series comprises four kinds of limestone and three of sandstone. Of these the Helderberg limestone is extensively used as a flagging stone, under various local names; it is also employed to some extent as a building material; the Oriskany sandstone is also used as a building material; it occasionally contains lime. Of the remaining layers, one of the sandstones is dark, shaly and brittle; the other calcareous and abounding in fossils. Two of the limestones contain large quantities of fossils, and derive their names from that

fact; in one the encrinite, one of the most beautiful of the crustaceous fossils, is predominant; in the other, the pentamerus, whose shell bears some resemblance, in form, to that of the common oyster. The remaining limestone is slaty and easily decomposed.

The Helderberg limestone is cavernous, and many of its caves have been explored for a considerable distance. They contain stalactites and stalagmites of great beauty.

The principal minerals of this formation are bog iron ore, calcareous and fluor spar, jasper, sulphate of strontian, in great abundance, satin spar, alum, bitumen and small veins of anthracite. The soil, overlying these rocks, is generally either a fine clay, or sand lying upon clay. Marl occurs quite frequently. By suitable cultivation it yields good crops of wheat and other grains. The timber is usually oak, chestnut, hickory, pine and hemlock.

This group occupies a narrow tract, commencing in the western part of Orange county, and passing northeasterly through Ulster to the Hudson; thence along the banks of that river, to Albany county, where it turns westwardly, passes through the centre of the state immediately south of the Ontario group, forming the bed of most of the small lakes in western New York, and terminates on the shores of Lake Erie.

The Erie Group is divisible into two portions, the lower, denominated Ludlowville shales, is composed of soft slaty rocks, alternating with thin beds of limestone, and is easily decomposed; the upper, called the Chemung group, consists of thin, even beds of gray sandstone, with intervening shales, or beds of slate.

Some of the fossils, found in this group, possess great beauty, and show the approach to that period of vegetable luxuriance, which marks the coal formation. Ferns, and other vegetable fossils frequently occur, and the avicula, delthyris and other shell fish, strongly resembling some living species, are found imbedded in the rocks.

The minerals of this group are few, and of no great importance. Petroleum, or mineral oil, called, in some parts of the state, Seneca oil, occurs in several localities, and the shale is often so strongly impregnated with it as to burn quite freely. Carburetted hydrogen, or inflammable gas, also issues from the surface in a number of places, and in such quantities, as to be used, in one or two instances, for illuminating villages, light houses, &c.

The soil where the Ludlowville shales form the surface rock, though apparently rough and broken, is rendered fertile by the constant decomposition of the rock. It is well adapted to the culture of wheat and other grains. As we ascend, to the more elevated surface of the Chemung sandstone, we find a marked change in the character of the soil; the white pine and hemlock take the place of the oak, maple and beech of the lower lands, and attain a gigantic growth. These lands produce the grasses luxuriantly, and, as they become cleared, will afford pasturage to vast herds of cattle and sheep.

The Erie group covers nearly the whole of Chautauque, Cattaraugus, Wyoming, Allegany, Steuben, Yates, Tompkins, Chemung and Tioga counties, together with portions of Broome, Chenango, Cortland, Ontario, Livingston, Genesee and Erie, as well as a narrow tract in Sullivan, Ulster, Greene, Schoharie and Otsego counties. This completes what, for convenience, has been termed the New

York Transition system. The remaining group properly belongs to the Transition system of the English Geologists, and is by them denominated the Old Red sandstone, that rock being its principal constituent. The State Geologists, from the fact of its being the predominant rock of the Catskill mountains, have given it the name of the Catskill group.

It consists of two distinct formations, viz., the Old Red sandstone overlying the Chemung sandstone, and the conglomerate strata, which are immediately beneath the coal bearing limestone of Pennsylvania. Between the layers of the former are interposed soft shales combined with mica.

The sandstone is generally of a deep red color, and imparts the same hue to the soil which covers it. It contains comparatively few fossils; the scales and bones of some lizard-like fish have been discovered in it.

The minerals of this group are few, and of but little importance. Bog iron ore and calcareous spar are those most worthy of notice. The conglomerate affords fine grindstones, and has been used to some extent for millstones.

The soil is generally good; the sandstone decomposing readily under atmospheric influence, mingles with the vegetable mould and renders it fertile. Hemlock, beech, maple, elm, basswood, butternut, &c. are the principal timber trees; the oak is seldom found in this formation.

The Red sandstone of the Catskill group is mostly confined to the vicinity of the Kaatsbergs; occupying the county of Delaware, and portions of Sullivan, Ulster, Greene, Otsego, Chenango and Broome; but the conglomerate extends westward, and caps the highest hills of the southwestern counties.

The Diluvial deposits skirt the shores of the St. Lawrence, Lake Champlain, and the Hudson, and compose the surface of the northern half of Long Island. They consist of a stiff blue clay beneath, a yellowish brown clay above this, and sand on the surface. The marine shells, found in these clays, belonging in some instances to extinct species, show that these deposits were made at an earlier period than those thrown down by rivers or oceans, in modern times. To this system belong also the boulders, scattered so widely over the

state.

The Alluvial deposits, consisting of gravel, sand, loam, &c. thrown up by the waves, or deposited on the shores of lakes, and the banks of rivers, and still in the process of aggregation, constitute the last of the geological formations of the state. To these belong portions of the valleys of the rivers and lakes and the southern half of Long Island. The soil of both these classes of deposits is usually fertile. The class of rocks known as trap and porphyry, do not, in this state, constitute a separate formation. They occur either in columnar masses like the Palisades, on the west bank of the Hudson, near New York, or in narrow veins or dikes, traversing rocks of an entirely different constitution. They are evidently the result of the action of subterranean fire. Porphyry is only found occupying a tract of a few miles in length, on Lake Champlain.

In connexion with the Geology of the state, the "Ridge road" is deserving of notice. This road consists of a bank of sand, gravel and