As I was strolling along the beach at the base of these basaltic cliffs, collecting minerals, and occasionally recent shells at low tide, I stopped short at the sight of an unexpected phenomenon. The solitary inhabitant of a desert island could scarcely have been more startled by a human foot-print in the sand, than I was on beholding some recent furrows on a ledge of sandstone under my feet, the exact counterpart of those grooves of ancient date which I have so often described in this work, and attributed to glacial action. After having searched in vain at Quebec (see p. 136.) for such indications of a modern date, I had despaired of witnessing any in this part of the world. I was now satisfied that, whatever might be their origin, those before me were quite

recent.

The inferior beds of soft sandstone, a, a, fig. 16.,

Section of the Cliff and Beach at Cape Blomidon.

a, a. Ledges of soft sandstone exposed at low water.

b. Red marls with light greenish streaks, and layers of fibrous gypsum.
c. Capping of trap.

d. Talus of blocks and pebbles of trap, amygdaloid, greenstone, &c.

which are exposed at low water at the base of the cliff at Cape Blomidon, form a broad ledge of bare rock, to the surface of which no sea-weed or barnacles can attach themselves, as the stone is always wearing away slowly by the continual passage of sand and gravel, washed over it from the talus of fallen fragments, d, which lies at the foot of the cliff on the beach above. The slow but constant undermining of the perpendicular cliff forming this promontory, round which the powerful currents caused by the tide sweep backwards and forwards with prodigious velocity, must satisfy every geologist that the denudation by which the ledge in question has been exposed to view is of modern date. Whether the rocks forming the cliff extended so far as the points a, 10, 50, or 100 years ago, I have no means of estimating; but the exact date and rate

Fig. 17.

Recent furrows on ledge of sandstone at Cape Blomidon.

of destruction are immaterial.

On this recently

formed ledge, I saw several straight furrows half an

inch broad, some of them very nearly parallel, as a, b, fig. 17., others diverging, as c, the direction of a, b, being N. 35° E., or corresponding to that of the shore at this point. After walking about a quarter of a mile, I found another set of similar furrows, having the same general direction within five degrees ; and I made up my mind that if these grooves could not be referred to the modern instrumentality of ice, it would throw no small doubt on the glacial hypothesis. When I asked my guide, a peasant of the neighbourhood, whether he had ever seen much ice on the spot where we stood, the heat was so excessive (for we were in the latitude of the south of France, 45° N.) that I seemed to be putting a strange question. He replied that in the preceding winter of 1841 he had seen the ice, in spite of the tide, which ran at the rate of 10 miles an hour, extending in one uninterrupted mass from the shore where we stood to the opposite coast at Parrsborough, and that the icy blocks, heaped on each other, and frozen together or "packed," at the foot of Cape Blomidon, were often fifteen feet thick, and were pushed along when the tide rose, over the sandstone ledges. He also stated that fragments of the "black stone" which fell from the summit of the cliff, a pile of which, d, fig. 16., lay at its base, were often frozen into the ice, and moved along with it. I then examined these

fallen blocks of amygdaloid scattered round me, and observed in them numerous geodes coated with quartz crystals. I have no doubt that the hardness of these gravers, firmly fixed in masses of ice, which, although only fifteen feet thick, are often of considerable horizontal extent, have furnished sufficient pressure and mechanical power to groove the ledge of soft sandstone.

In Nova Scotia the term "loaded ice" is in common use for large sheets of ice several acres in area, which are sometimes floated off from the rivers as the tide rises, with sedge and other salt-marsh plants frozen into their lower surfaces; also with mud adhering plentifully to their roots. In our speculations, therefore, on the carrying power of ice, we ought always to remember that, besides gravel and large fragments of rock, it transports with it the finest mud.

Dr. Harding informed me that the surface of mudbanks along the estuaries near Wolfville, are often furrowed with long, straight, and parallel ruts, as if large waggons had passed over them. These conform in their general direction to the shore, and are produced by the projecting edges of irregular masses of packed ice, borne along by the tidal

current.

CHAPTER XXIV.

Coal Formation of Nova Scotia.- Productive Coal Measures.Erect Fossil Trees in the Cliffs of the Bay of Fundy.-Section from Minudie to the South Joggins.— Ten buried Forests, one above the other.- Connexion of upright Trees with Seams of Coal. Stigmaria. — Sigillaria.- Evidence of repeated Submergence of dry Land. - Theory to explain the Evenness of the ancient Surface.-Pictou Coal-field.-Bed of erect Calamites, compared to those of St. Etienne in France.— List of Species of Nova Scotia Coal-plants.— Four-fifths of these Fossils identified with European Species. - Carboniferous Flora of the United States.

ABOVE the granite, clay-slate, quartzite, and Silurian formations of Nova Scotia, there occur, in the northern part of the peninsula, as stated in the last chapter, strata referable to the carboniferous group, occupying very extensive tracts, and resting unconformably on the rocks of the older series. They may be divided into three formations; the middle one, comprising the productive coal-measures, agreeing precisely with those of Europe in their lithological characters and organic remains; an upper one, composed of sandstone and shale with fossil plants, but without coal; and a lower carboniferous carboniferous group, chiefly made up of red sandstone and red marl, with subordinate beds of gypsum and marine limestone.