Chapter XV. Hard Rocks and Hard Talk.

ACCOMPANIED by an agreeable local geologist, Horace had his geological as well as botanical rambles.

The first hill behind Hobart Town is Knocklofty. The green bossy head is bare of trees. But what a charming view did he thence obtain! The harbour lay below, with its snug little coves, into which shadows of gardens were dipping,—with its proud masted vessels, with the haunts of men by its side, and the laughing lads and lassies who paddled on its bosom. Seabirds screamed over it with delight, and land songsters raised their notes as they darted across it from shore to shore. The sun cheered it by day, the moon threw its chastening beams upon it by night. The sage stars twinkled their telegraphic communications to the ripples, that rose as if they would like to salute those watching, loving orbs.

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Then a look up the New Town Valley brought such a change again. Man had gladly appropriated the charms so exposed to his gaze. How dearly had nature rewarded his service and affection! The gentle rises heaved with pleasure, revealing ever varying beauties. The plain was blooming with floral loveliness. The fields were smiling with luxuriance. The orchards, the pride of the valley, were hanging about babbling brooks, sheltering happy homesteads, and nodding over the teamster on the road.

Some of the gardens crept down to the river, and others clambered up to the forests of Wellington. There rested the village, reposing amidst garlands. The school-bell scattered groups of wayside gambollers. A distant sheep-bell sounded down the valley lazily on the still air. Here were proud mansions of wealth, and there were lowlier tenements, though not abodes of poverty. All alike were embosomed among trees, were encircled by flowers, and were fanned by healthful breezes.

From gazing around Horace turned to the rock on which he stood. It was the igneous greenstone.

‘Here,’ said Mr Wanfel, “the boiling, bubbling mass cut off the sandstone of Mount Wellington from the sandstone of the domain on the other side of the town.’

‘What an astonishing quantity of this formation you have here in Tasmania,’ exclaimed his listener.

‘Few, if any, countries can boast of such a proportion.

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It exceeds in area the basalt. Of a livelier colour than its companion, it is often harder in structure, though both are worthy of the ordinary appellation of ironstone.’

‘You spoke just now of the sandstone. What is that?’

‘Well, as we have a good view here, I can speak of the formations better. This greenstone overflowed the sandstone here, and did not seriously affect the horizontal of the rock. But a worse foe to the peaceful existence of the sandstone was a devastating deluge, which tore huge gaps hundreds of feet in depth, and left here and there platforms or shelves to mark the shores of its ravages.’

‘But what sandstone is this I find alike by the side of Mount Wellington, by the Domain, by Kangaroo Point across the harbour, and up that sweet vale of New Town?

‘It corresponds to the Liverpool sandstone, and serves as the burial slab over the remains of ancient forests turning into coal. As you have heard, it is, where extra silicified, an unequalled building stone.’

‘Yes, the excellence of your own public edifices is a proof of it. The finest, whitest specimens you appear to ship off to your richer neighbours of Melbourne and Sydney for the adornment of their palaces.’

‘Yes, we poor Tasmanians must make something out of the golden colony across the Strait. They have shut out our produce from their market pretty well

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by their newly revived old doctrine of Protection. They may grow corn and carrots, and gather apples and apricots; but they have nothing for their building ornaments like our Hobart Town sandstone, the white liver rock.’

‘What fossils does it contain?’

‘They are few and far between. They must have got washed down to the claybeds below. The carboniferous claystones or mudstones are fully four hundred feet thick, and have a sufficient display of ancient life to interest the geologist. Below this again we have the limestone.’

‘When at the muscum, Mr Wanfel, I was surprised to find such an absence of fish in your carboniferous beds.’

‘True; but you could not fail to notice the wonderful similarity of our fossils with those of the like formations in England.’

‘That surprised many at home. It had been evidently considered at one time of day that, because your vegetation was so peculiar, and your animal life so peculiar, all your fossil existence should have been as strange and peculiar. There have been occasions, therefore, when this Tasmanian part of the world must have exhibited identical phases of being with Britain.’

‘A shrewd guess of yours, Mr Douglas. When a clever Frenchman undertook to prove that all our Australian region had dropped from the moon, our dissimilarity to Europe must have struck the

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learned. But gradually we have been urging and establishing our claim of kinship. Fossil after fossil rose up to confirm the story of our relation.’

‘Indeed you may say that, since Professor M'Coy has sent to London such magnificent specimens of southern Ichthyosauri, those monstrous fish-lizards of olden times.’

‘And, allow me to add, since this very sandstone of ours has revealed a Labyrinthodon.’

‘Where was it found?’

‘Some of us disinterred it from the Triassic quarry in the Domain, not far from the Derwent. At first only two leg bones were turned out. It was some time before we could be believed that this enormous frog-like croaker of the old world had once given his hop of a dozen feet at a time on this side of the Line.’

‘Pray,’ enquired Horace, ‘is that limestone we saw as we came up the hill the same as that beneath your claystone and sandstone?’

‘Certainly not. But we shall get a better sight in the Gerlstown Bay over the Derwent, some day.’

Not long after this conversation the same couple took a row across. The limestone was being then burned in kilns.

‘Ah!’ cried the young man; ‘you have a tilt here.’

‘We have; but don't you see that black basalt between us and the river? That was the intruder.’

‘But what a curious stone we have here!’

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‘It is a Travertine. Fresh water deposits were brought into this basin. You can distinguish them in that section. There you have one hundred feet depth. Three beds of different thicknesses of Travertine can be distinguished; they range from ten to fifteen feet each.’

‘Is this a recent formation, Mr Wanfel?’

‘Yes. I have gathered bones from these beds still holding their phosphoric acid, and preserving their very cellular tissues.’

‘That must be post-tertiary. But if so, your tilting basalt would be younger still.’

‘It would so. But what is more marvellous, there are pretty good grounds for belief that this noble river Derwent had then no existence, or else ran elsewhere.’

‘Those were changes.’

‘But not the only recent ones I could show you,’ added Mr Wanfel. ‘Just beyond, to the south of this spot, are the oyster-beds of Sorell, stuck up one hundred feet from the sea level now. They are clearly but a fragment of an extensive bank.’

‘Another of your wonderful denudations, sir. But, amidst all your stirring recent times, I fail to discover the ordinary Vesuvian displays, such as, I am told, so commonly show themselves in Victoria, as well as New Zealand.’

‘Right. We have any amount of Greenstone, Basalt, Trachyte, thrusting themselves forward in primitive, secondary, and tertiary days, but no modern

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lavas. You may pick up fragments of scoria on the cornelian strand of Sandy Bay there, but no ash from exalted volcanoes has fallen this way.’

‘Yet you are not wanting in fragments of petrified wood. I often come upon these in my walks.’

‘And may find them for fifty miles up the Derwent. By all means visit the petrified tree on the Macquarie plains, on the other side of New Norfolk.’

‘Thank you, I hope to do it. But is that silicified like my collection?’

‘It is embedded in a Greenstone floor, and is converted into opal. But have you been to Rose Garland, on the Derwent?’

‘Not yet.’

‘Then you have a geological treat in store. There, in some very recently formed sandstone, perhaps Pleistocene, you have some curious masses of greenstone enclosed. It is a plum-pudding, with plums six or seven feet long.’

‘Then I must surely go there. But I should like you to inspect a cave not far from my house, in Glenorchy.’

‘I think I know where you mean. I have crawled in there more than once.’

‘What a singular chasm in the greenstone! Some of the chambers are pretty large, but others have far too low a roof for comfort. I did not admire going lower than all fours in some of the passages.’

‘You missed a treat by your lack of creeping exercise.

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I came upon a treasure by submitting to a kind of worm-wriggling in those recesses.’

‘And what was your discovery?’

‘Some bones of original kangaroos and opossums. How they got in, unless washed there in broken detachments, I know not, as the space would never permit of their walking to that retreat.’

‘Do you suppose that a long time ago?’

‘I do; for the soil in which they were found indicated it. You may remember that Major Mitchell turned out kangaroo remains from a limestone cave in New South Wales, digging them out of red earth. Professor Owen declared that the hoppers of those distant periods, and on those ancient plains, were at least a dozen feet in height.’

Mr Wanfel was great in coal, and took his young friend Horace over the field just outside of Hobart Town. On the New Town side of Mount Wellington the carbonaceous material is procured.

‘You see,’ observed the geologist, ‘that the carboniferous rocks have been greatly denuded. Huge masses have been torn away and carried off.’

‘What age may this coal be?’ asked Horace.

‘I fancy Mesozoic; and, therefore, younger than the coal deposit of Newcastle in New South Wales. We passed the shale cropping out on the rise outside of the town by the road side.’

‘But the coal is not bituminous.’

‘No, it is but anthracite and yields no flame, while

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producing a good fire. Whether the igneous greenstone and basalt eruptions have changed the substance or no, we say not. But across the Derwent, a few miles hence, there is excellent bituminous stuff, giving a good flame and leaving but a little white ash.’

‘Where is this?’

‘It is all along the Coal river which flows by Richmond, and near Jerusalem. The Jerusalem coal has been much admired; but the quantity is too little to pay labour. The carboniferous superincumbent sandstone is nearly one thousand feet thick at Richmond, a dozen miles the other side of the river.’

‘How odd it seems to talk about coal at Jerusalem!’ the young man remarked. ‘How different now would be the circumstances of the celebrated town of Palestine, had its limestone beds been of an earlier age than they are, and belonged to the carboniferous instead of the cretaceous system!’

‘Speaking of limestone, let us inspect our Wellington formation,’ said the geologist.

They travelled towards it. Horace was struck with the singular fact that everywhere the fossils were only casts of the shells, but some stones were a perfect mass of these remains of past life.

The Butterfly, as the colonial lads called the Spirifer, was in the greatest abundance. The Productus, the Pecten, the Terebratula, the Crinoidal columns, the singular crustaceous Trilobite, the plant Phyllatheca, and the lovely lace coral Fenestella, all declared the

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position to be Palæozoic. Casts of fossil plants of this primitive age have been seen up the mountain as high as 3500 feet. The hone beds of the hill are 600 feet thick.

‘Well,’ said Horace, ‘if we have not the gold here in payable quantity, there is geology enough greatly to interest the rambler.’

‘Yes, and some day our high per centage iron ores will be well wrought, and the good coal of the east coast be more profitably worked. Then will our geology attract the commercial man as well as the student.’