In this lower series there are also occasionally some beds of shale with plants, and some coal-grits, and thin seams of impure coal.

A variety of opinions have been entertained respecting the true age and position of the last-mentioned or gypsiferous formation, which has been generally presumed to be newer than the coal,—by some referred to the New Red sandstone, and even thought to overlie the coal-measures unconformably. Immediately after my return to England, I communicated to the Geological Society my opinion; 1st, that the gypsiferous formation, with its accompanying fossiliferous limestones, is a true member of the Carboniferous group; 2dly, that its position is below the productive coal-measures.*

I shall now give some account of these middle or productive coal-measures, which contain valuable seams of bituminous coal, at various places, especially near Pictou. I was particularly desirous, before I left England, of examining the numerous fossil trees alluded to by Dr. Gesner as imbedded in an upright posture at many different levels in the cliffs of the South Joggins, near Minudie. These cliffs belong to the Cumberland coal field, on the southern shores of a branch of the Bay of Fundy, called the Chig

*See Proceedings of Geol. Soc., vol. iv. p. 184. 1843.

necto Channel, which divides part of New Brunswick from Nova Scotia. The first allusion to the trees which I have met with, is that published in 1829 by Mr. Richard Brown, in Halyburton's Nova Scotia, and he attributed their fossilisation to the inundation of the ground on which the forests stood. I felt con-. vinced that, if I could verify the accounts of which I had read, of the superposition of so many different tiers of trees, each representing forests which grew in succession on the same area, one above the other; and if I could prove at the same time their connexion with seams of coal, it would go farther than any facts yet recorded to confirm the theory that coal in general is derived from vegetables produced on the spots where the carbonaceous matter is now stored up in the earth.

At Wolfville I hired a schooner, which soon carried us across the Basin of Mines to Parrsborough. We had a side wind, and the deck was inclined at about an angle of 45°, in spite of which we admired a splendid view of the coast, and the range of basaltic rocks which extend from Cape Blomidon to Cape Split. At Parrsborough I was joined by Dr. Gesner, who had come expressly from New Brunswick to meet me; and we went together to Minudie, a thriving village, where we were hospitably received by the chief proprietor and owner of the land, and of

many of those fertile flats of red mud before described, which he has redeemed from the sea.

From Minudie, a range of perpendicular cliffs extends in a south-westerly direction along the southern shore of what is commonly called the Chignecto Channel. The general dip of the beds is southerly, and the lowest strata near Minudie consist of beds of red sandstone, with some limestone and gypsum, a, b, fig. 18. The section is then very obscure for about three miles, or from b to c, the rocks consisting chiefly of red sandstone and red marl, after which, at c, blue grits are seen, inclined to the S.S.W. at an angle of 27°, affording an excellent grindstone, and attaining a thickness of forty-four feet. These beds are succeeded to the south by a vast series of newer and conformable strata, all dipping the same way, and, for the first three miles which I examined, inclined nearly at the same angle, upon an average about 24° S.S.W. Within this space, or between d and g, all the upright trees hitherto found occur; but the same set of strata is still continuous, with a gradually lessening dip, many miles farther to the

south.

If we assign a thickness of four or five miles to this regular succession of carboniferous strata, which, as I shall afterwards show, must have been originally quite horizontal, our estimate will probably be rather

under than over the mark. For the first mile south of the grindstones, or from c to d, I observed no coal in the cliffs, after which the first of the upright trees appears at d, at the distance of about six miles from Minudie. Then followed a series of coal-bearing strata, consisting of white freestone, bituminous shale, micaceous sandstone, sandy clays, blue shale, and clays with and without nodules of ironstone, all resembling the carboniferous rocks of Europe. They occupy a range of coast about two miles long, the vertical height of the cliffs being from 150 to 200 feet; and about nineteen seams of coal have been met with, which vary in thickness from two inches to four feet. At low tide, we had not only the advantage of beholding a fine exposure of the edges of these beds in the vertical precipices, but also a horizontal section of the same on the beach at our feet.

The beds through which erect trees, or rather the trunks of trees, placed at right angles to the planes of stratification, are traceable, have a thickness of about 2500 feet; and no deception can arise from the repetition of the same beds owing to shifts or faults, the section being unbroken, and the rocks, with the exception of their dip, being quite undisturbed. The first of the upright trees which I saw, in the strata d, fig. 18., is represented in the enlarged section, fig. 19. No part of the original plant is preserved except the bark, which forms a tube of pure