Upon this latter, at Kincardine, thirty miles north-east of Goderich, another well was sunk last year, and showed the exist ence of the salt-bearing stratum at a depth of about 900 feet. The record of the boring furnished me was as follows:

By comparing the above result with that obtained in the first well at Goderich, it will be seen that while the amount of shaly strata from the base of the limestone to the bottom of the salt was only 205 feet at Goderich, it attains at Kincardine a thickness of 309 feet; in which, however, are included thirty feet of a rock described as limestone, but which may perhaps be gypsum, masses of which were encountered in the shales in boring at Goderich. Of the 775 feet of limestone belonging to the formation at Goderich, only 508 remain at Kincardine, the upper portion being removed by erosion. It is not, however, certain that the original thickness of the Onondaga, or Salina formation as it is sometimes called, was precisely the same here as at Goderich, and thus the amount which has been removed by erosion may be somewhat greater or less than would at first appear. In like manner, the thickness of the same formation at Clinton may differ somewhat from that at Goderich, so that the overlying portion of Corniferous limestone at that place may be greater or less than 200 feet, according as the volume of the Salina formation is less or greater than at Goderich. Careful examinations of future borings would enable us to determine these important points, and for this end. samples of the material extracted at intervals of fifteen or twenty feet, should be carefully preserved.

The base of the Onondaga formation comes to the surface at the mouth of the Saugeen river. Here, at Southampton, an illadvised attempt was last year made in search of salt by boring. According to the record furnished me, the solid rock was only

reached at a depth of 230 feet,* after which 350 feet of white and gray limestone had been penetrated up to August 22, 1868. The subsequent record is incomplete, but beneath the limestones were encountered several hundred feet of red shales, and the boring was finally abandoned at a depth of 1,251 feet from the surface. Another well also was sunk last year at Port Elgin, five miles below Southampton, on the coast, and the boring in November last, had attained a depth of 890 feet, and was still going on in the red shales. In this connection may be noticed a well which was sunk in 1867, at the village of Waterloo, about eighty miles to the south-east of Port Elgin, but in the same geological position, that is to say near the base of the Onondaga formation, and was abandoned at the depth of 1,120 feet. The record of the boring was as follows:

At this depth the well was abandoned; bitter saline waters were met with at depths of 800 and 900 feet, and were probably similar to the bitter water found at St. Catherines at the same geological horizon. In the Report for 1866, on pages 271, 272, the waters of this class are noticed, and their unfitness for the manufacture of salt pointed out. The 77 feet of limestone, gypsum and shale in the Waterloo section belong to the base of the Onondaga, or salt-bearing series, beneath which no valuable brines.

The account of this portion of the boring is as follows:
Gravel and sand, with trunks of trees at the base.. 23 Feet.

For a notice of the superficial deposits of this region, see the

Geology of Canada, page 897.

have yet been found. The 340 feet of limestone underlying the shale, represent the Guelph, Niagara and Clinton formations, and the red and blue shales beneath these belong to the Medina formation. By referring to the account of a boring at Barton, near Hamilton, it will be seen that these shales have there a total thickness of about 600 feet. (Report for 1866, page 251.)

It will be noticed that the Onondaga formation, as shewn in the borings of Goderich and its vicinity, consists of several hundred feet of limestone, chiefly magnesian, underlaid by two or three hundred feet of red and blue shales, which carry rock-salt at their base. These are succeeded, in descending order, by the magnesian limestones of the Guelph, Niagara and Clinton formations, which rest upon the red shales of the Medina, as seen in the Southampton and Waterloo borings. We have the following succession in going downwards:

1. Limestones of the Onondaga or Salina formation.;
2. Red and blue shales of the same.

3. Limestones of the Guelph and Niagara formations.
4. Red and blue shales of the Medina formation.

On account of the resemblances in color between the upper and lower couples of the above series mistakes may easily occur, as at Southampton, where the strata of 3 and 4 were supposed to be those of 1 and 2. Such errors, which have caused the expenditure of considerable sums of money at Southampton, Port Elgin, and Waterloo, would be avoided by a careful study of the distribution of the various geological formations of this region, as described in the Geology of Canada. The accuracy with which the limits of the various formations throughout this region were traced out by Mr. Alex. Murray, has received repeated confirmation in the course of the various explorations for oil and salt which have been made within the past few years.

As regards the possible extent of the salt-bearing area now under consideration, I take the liberty of quoting the following passage from my Report for 1866, page 271:

With regard to the probabilities of obtaining salt wells by other borings in this region, it is to be remarked that the thickness of the deposit of salt traversed in the Goderich well may warrant us in expecting that its area may be considerable; though whether its greatest extent will be inland, or beneath the waters of the lake, can only be known by experiment. It has already been explained that salt deposits have been formed in basins

whose limits were determined by the geographical surface at the time; and it is worthy of remark that both here and in New York the salt deposits are connected with a thickening of the Onondaga formation, which, in its thinner intermediate portion, is appar ently almost destitute of salt; a fact suggesting former geographical depressions, in which the two salt bearing portions of the formation may have been deposited. Although it would be unsafe to predict that this development of salt at the base of the Onondaga formation is so widely extended, its thickness at Tilsonburg, St. Mary's, London, and Enniskillen, is such, that it seems probable that farther borings in these localities, where deep wells have already been sunk, may reach saliferous strata capable of yielding valuable brines."

In confirmation of the first portion of the above extract, we can now point to the existence of salt at Clinton, thirteen miles to the S.E., and at Kincardine, thirty miles N.N.E. of Goderich. These two stations are forty miles apart, and a line connecting them. would pass about seven miles to the east of Goderich. It is, therefore, extremely probable that the whole region between Clinton and Kincardine will be found underlaid by salt, and may belong to a single basin, whose extent yet remains to be ascertained.

The success of the borings at Goderich and in its vicinity has, as we have seen, led to the sinking of wells for brine, below the salt-bearing horizon. At the same time, other trials have been made in the hope of reaching it, by boring through rocks overlying those of the Goderich region. For the information of inquirers, it may therefore be well to recall briefly some of the facts with regard to the nature and thickness of these rocks, of which the details are given in my Report for 1866. It will there be seen that the most recent rocky strata in south-western Ontario are the greenish sandstones of the Portage formation. These pass downwards into hard black slates (the so-called Genessee slates) which, in their turn, rest upon the soft gray strata of the Hamilton formation. This group of sandstone and hard shale, which appears at the surface at Kettle Point in Bosanquet, and also in Warwick, is generally concealed by the clays of the region; but from the records of numerous borings, chiefly made in search of petroleum, we have been enabled to determine its thickness in many places. Thus, in a boring at Corunna, on the St. Clair river, near Sarnia, it measures 213 feet; in two borings in Cam

den, 146 and 200; in Sombra, 100; in Alvinstone, eighty feet; in Warwick, and near Wyoming station, about fifty; a little north of Bothwell, about eighty; and further south, towards the shore of Lake Erie, about sixty feet in thickness. It will be understood that this varying thickness is due to the erosion along the anticlinals, before the deposition of the clays, so that in many parts of the region only the lower portions of the black slates remain, while in other places they are entirely wanting.

The hard strata just described are conformably underlaid by those of the Hamilton formation, which in some parts of New York attains a thickness of 1,000 feet, but is reduced to 200 feet in the western part of the State. It consists, in Ontario, chiefly of soft grey marls, called soapstone by the well-borers, but includes at its base a few feet of black beds, probably representing the Marcellus shale. It contains, moreover, in some parts, beds of from two to five feet of solid gray limestone, holding silicified fossils, and in one instance impregnated with petroleum; characters which, but for the nature of the organic remains, and for the associated marls, would lead to the conclusion that the underlying Corniferous limestone had been reached. The thickness of the Hamilton formation varies in different parts of the region under consideration. From the record of numerous wells in the southwestern portion it appears that the entire thickness of soft strata between the Corniferous limestone below and the black shale above, varies from 275 to 230 feet, while along the shore of Lake Erie, it is not more than 200 feet. Further north, in Bosanquet, beneath the black shale, 350 feet of gray shale were traversed in boring, without reaching the hard rock beneath; while in the adjacent township of Warwick, in a similar boring, the underlying limestone was reached 396 feet from the base of the black shales. It thus appears that the Hamilton shale (including the insignificant representative of the Marcellus shale at its base) augments in volume from 200 feet on Lake Erie to about 400 feet near to Lake Huron.

The Hamilton formation, as just defined, rests directly upon the solid non-magnesian limestones of the Corniferous formation. The thickness of this formation in western New York is about ninety feet, and in southern Michigan is said to be not more than sixty, although it increases in going northward, and attains 275 feet at Mackinac. In the townships of Woodhouse and Townsend its thickness has been found to be 160 feet; but for a great