Narrative of a Survey of the Intertropical and Western Coasts of Australia Volume II Part 56

Captain King's specimens from Lacrosse Island are not to be distinguished from the slaty strata of that formation, in the banks of the Avon, about two miles below Clifton.)

From hence to Cape Londonderry, towards the south, is an uniform coast of moderate elevation; and from that point to Cape Leveque, although the outline may be in a general view considered as ranging from north-east to south-west,* the coast is remarkably indented, and the adjoining sea irregularly studded with very numerous islands. The specimens from this tract consist almost entirely of sandstone, resembling that of Cambridge Gulf, Goulburn Island, and the Gulf of Carpentaria; with which the trap-formation appears to be a.s.sociated.

(*Footnote. The large chart Sheet 5 best shows the general range of the sh.o.r.e, from the islands filling up the inlets.)

York Sound, one of the princ.i.p.al inlets on this part of the coast, is bounded by precipitous rocks, from one to two hundred feet in height; and some conical rocky peaks, which not improbably consist of quartz-rock, were noticed on the eastern side of the entrance. An unpublished sketch, by Captain King, shows that the banks of Hunter's River, one of the branches of York Sound, at seven or eight miles from its opening, are composed of sandstone, in beds of great regularity; and this place is also remarkable for a copious spring of fresh water, one of the rarest phenomena of these thirsty and inhospitable sh.o.r.es.*

(*Footnote. Narrative 1.)

The most considerable inlet, however, which has yet been discovered in this quarter of Australia, is Prince Regent's River, about thirty miles to the south-west of York Sound, the course of which is almost rectilinear for about fifty miles in a south-eastern direction; a fact which will probably be found to be connected with the geological structure of the country. The general character of the banks, which are lofty and abrupt, is precisely the same with that of the rivers falling into York Sound; and the level of the country does not appear to be higher in the interior than near the coast. The banks are from two to four hundred feet in height, and consist of close-grained siliceous sandstone, of a reddish hue;* and the view (Plate above) shows that the beds are nearly horizontal, and very regularly disposed; the cascade there represented being about one hundred and sixty feet in height, and the beds from six to twelve feet in thickness. Two conspicuous hills, which Captain King has named Mounts Trafalgar and Waterloo, on the north-east of Prince-Regent's River, not far from its entrance, are remarkable for cap-like summits, much resembling those which characterize the trap formation. (Sketch 3.)

(*Footnote. Narrative 1 and 2.)

The coast on the south of this remarkable river, to Cape Leveque, has not yet been thoroughly examined; but it appears from Captain King's Chart (Number 5) to be intersected by several inlets of considerable size, to trace which to their termination is still a point of great interest in the physical geography of New Holland. The s.p.a.ce thus left to be explored, from the Champagny Isles to Cape Leveque, corresponds to more than one hundred miles in a direct line; within which extent nothing but islands and detached portions of land have yet been observed. One large inlet especially, on the south-east of Cape Leveque, appears to afford considerable promise of a river; and the rise of the tide within the Buccaneer's Archipelago, where there is another unexplored opening, is no less than thirty-seven feet.

The outline of the coast about Cape Leveque itself is low, waving, and rounded; and the hue for which the cliffs are remarkable in so many parts of the coast to the north, is also observable here, the colour of the rocks at Point Coulomb being of a deep red: but on the south of the high ground near that Point, the rugged stony cliffs are succeeded by a long tract, which to the French voyagers (for it was not examined by Captain King) appeared to consist of low and sandy land, fronted by extensive shoals. It has. .h.i.therto been seen, however, only at a distance; so that a s.p.a.ce of more than three hundred miles, from Point Gantheaume nearly to Cape Lambert, still remains to be accurately surveyed.

Depuch Island, east of Dampier's Archipelago, about lat.i.tude 20 degrees 30 minutes, is described by the French naturalists as consisting in a great measure of columnar rocks, which they supposed to be VOLCANIC; and they found reason to believe that the adjoining continent was of the same materials.* It is not improbable, however, that this term was applied to columns belonging to the trap formation, since no burning mountain has been any where observed on the coast of New Holland: nor do the drawings of Depuch Island, made on board Captain King's vessel, give reason to suppose that it is at present eruptive. Captain King's specimens from Malus Island, in Dampier's Archipelago (sixty miles farther west) consist of greenstone and amygdaloid.

(*Footnote. Peron volume 1 page 130.)

The coast is again broken and rugged about Dampier's Archipelago, lat.i.tude 20 degrees 30 minutes; and on the south of Cape Preston, in lat.i.tude 21 degrees, is an opening of about fifteen miles in width, between rocky hills, which has not been explored. From thence to the bottom of Exmouth Gulf, more than one hundred and fifty miles, the coast is low and sandy, and does not exhibit any prominences. The west coast of Exmouth Gulf itself is formed by a promontory of level land, terminating in the North-west Cape; and from thence to the south-west, as far as Cape Cuvier, the general height of the coast is from four to five hundred feet; nor are any mountains visible over the coast range.

Several portions of the sh.o.r.e between Shark's Bay and Cape Naturaliste have been described in the account of Commodore Baudin's Expedition; but some parts still remain to be surveyed. From the specimens collected by Captain King and the French descriptions, it appears that the islands on the west of Shark's Bay abound in a concretional calcareous rock of very recent formation, similar to what is found on the sh.o.r.e in several other parts of New Holland, especially in the neighbourhood of King George's Sound; and which is abundant also on the coast of the West Indian Islands, and of the Mediterranean. Captain King's specimens of this production are from Dirk Hartog's and Rottnest Islands; and M. Peron states that the upper parts of Bernier and Dorre Islands are composed of a rock of the same nature. This part of the coast is covered in various places with extensive dunes of sand; but the nature of the base, on which both these and the calcareous formation repose, has not been ascertained.

The general direction of the rocky sh.o.r.e, from North-west Cape to Dirk Hartog's Island, is from the east of north to the west of south. On the south of the latter place the land turns towards the east. High, rocky and reddish cliffs have been seen indistinctly about lat.i.tude 27 degrees; and a coast of the same aspect has been surveyed, from Red Point, about lat.i.tude 28 degrees, for more than eighty miles to the south-west. The hills called Moresby's flat-topped Range, of which Mount Fairfax, lat.i.tude 28 degrees 45 minutes, is the highest point, occupy a s.p.a.ce of more than fifty miles from north to south.

Rottnest Island and its vicinity, lat.i.tude 32 degrees, contains in abundance the calcareous concretions already mentioned; which seem there to consist in a great measure of the remains of recent sh.e.l.ls, in considerable variety. The islands of this part of the sh.o.r.e have been described by MM. Peron and Freycinet;* and the coast to the south, down to Cape Leeuwin, the south-western extremity of New Holland, having been sufficiently examined by the French voyagers, was not surveyed by Captain King.

(*Footnote. Peron volume 2 page 168 etc.)

Swan River (Riviere des Cygnes) upon this part of the coast, lat.i.tude 31 degrees 25 minutes to 32 degrees, was examined by the French expedition, to the distance of about twenty leagues from its mouth; and found still to contain salt water. The rock in its neighbourhood consisted altogether of sandy and calcareous incrustations, in horizontal beds, enclosing, it is stated, sh.e.l.ls, and the roots and even trunks of trees. Between this river and Cape Peron, a "great bay" was left unexplored.*

(*Footnote. Peron volume 1 page 179. Freycinet page 5. 170.)

The prominent ma.s.s of land, which stands out from the main, between Cape Naturaliste and Cape Leeuwin, and runs nearly on the meridian for more than fifty miles, seems to have a base of granite, which, at Cape Naturaliste, is said to be stratified.* The same rock also occurs, among Captain King's specimens, from Bald-head in King George's Sound; but nearly on the summit of that hill, which is about five hundred feet high, were Found the ramified calcareous concretions, erroneously considered as corals by Vancouver and others;** but which appear, from Captain King's specimens, to be nothing more than a variety of the recent limestone so abundant throughout these sh.o.r.es.

(*Footnote. Peron volume 1 page 69.)

(**Footnote. Vancouver 1 49. D'Entrecasteaux 2 175. Freycinet 105.

Flinders 1 63. See the detailed descriptions hereafter; and Captain King's Narrative volume 1.)

The south coast, and the southern portion of the east coast of Australia, which were surveyed by Captain Flinders, are described in the account of his voyage, and do not come within the object of the present paper.

GEOLOGICAL REMARKS.

1. The rocks, of which specimens occur in the collections of Captain King and Mr. Brown, are the following:

Granite: Cape Cleveland; C. Grafton; Endeavour River; Lizard Island; Round Hill, near C. Grindall; Mount Caledon; Island near C. Arnhem; Melville Bay; Bald-head, King George's Sound.

Various Slaty Rocks: Mica-State: Mallison's I.

Talc-State: Endeavour River.

Slaty Clay: Inglis' I., Clack I., Percy I.

Hornblende Rock ?: Poba.s.soo's Island; Halfway Bay, Prince Regent's River.

Granular Quartz: Endeavour River; Montagu Sound, North-west Coast.

Epidote: C. Clinton ?; Port Warrender; Careening Bay.

Quartzose Conglomerates, and ancient Sandstones: Rodd's Bay; Islands of the north and north-west coasts; Cambridge Gulf; York Sound; Prince Regent's River.

Pipe-clay: Melville Bay; Goulburn I.; Lethbridge Bay.

ROCKS OF THE TRAP FORMATION.

Serpentine: Port Macquarie; Percy Isles.

Sienite: Rodd's Bay.

Porphyry: C. Cleveland.

Porphyritic Conglomerate: C. Clinton, Percy I., Good's I.

Compact Felspar: Percy I., Repulse Bay, Sunday Island.

Greenstone: Vansittart Bay, Bat I., Careening Bay, Malus I.

Clinkstone: Morgan's I., Poba.s.soo's I.

Amygdaloid, with Chalcedony: Port Warrender; Half-way Bay; Bat Island; Malus I.

Wacke ?: Bat Island.

Recent calcareous Breccia: Sweer's Island, N. coast. Dirk Hartog's and Rottnest Islands, etc., West coast. King George's Sound, South coast.

The only information that has been published respecting the geology of New Holland, besides what is contained in the Voyages of Captain Flinders and Commodore Baudin, is a slight notice by Professor Buckland of some specimens collected during Mr. Oxley's Expedition to the River Macquarie,* in 1818; and a brief outline of a paper by the Reverend Archdeacon Scott, ent.i.tled A Sketch of the Geology of New South Wales and Van Diemen's Land, which has been read before the Geological Society.**

On these authorities, the following may be added to the preceding list of rocks:

Limestone, resembling in the character of its organic remains the mountain limestone or England: Interior of New Holland, near the east coast; Van Diemen's Land (Buckland; Prevost ma.n.u.scripts; Scott).

The Coal-formation: East coast of New Holland; Van Diemen's Land.

(Buckland-Scott.)

Indications of the new red-Sandstone (Red-Marl) afforded by the occurrence of Salt: Van Diemen's Land. (Scott.)