WCP470

[1]

On the Wallaby!^{1, 2}

Corinda,¹

N[ea]r. Brisbane, Q[ueens]l[an]d.

12^th. Feb[ruar]y. 1910².

Dear friend Wallace.

By this time I hope you ^have received my 50.000 pp. incoherencies. I simply sat and wrote on & on as if I were having a chat again. Also I trust you have received the gems³ — I have not been to Brisbane since I wrote but so can[']t say if Sankey⁴ is back & has packed them off, but I saw his nephew at a council meeting of the Opth[almic]. Opt[icians]. Inst[itute]⁵ , and m[a]de[?] him very uncomfortable to the best of my ability and belief. so he is sure to have upbraided his uncle for the sake of peace.

I have several more things to indite⁶ unto thee with mine own hand and cannot tarry tilI see thee, for the way be long and it draweth to evening perchance for both of us.

Firstly as to the Aust[ralian]. Cretaceous⁷ and especially the much misunderstood Desert Sandstone (U[pper]. Cret[aceous].⁸). My friend L. C. Green⁹ (vide¹⁰ my paper) dropped in yesterday — hobbled in as a matter of fact — being a suddenly ^stricken rheumatic illustrative of the floods you were sceptical about. He had been, for the Geol[ogical].¹¹ , examining our N[ew].S[outh].W[ales]. borderland re artesian water, and the river I spoke of — the Barwon¹² — was dry a month ago, and when he left it a fortnight since was 4 miles wide near Goondiwindi¹³, and^{14 was} a lake lower down where a man he knew had been three days out of sight of land in a boat. For floods on the Murray¹⁵ in 1870 and 1890 when it was 60 miles wide & steamers landed cargo 25 miles inland, see Gregory's¹⁶ "Australia" [your old Stanford vol. new ed[ition].] p. 261.¹⁷ But to get on to the :-

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2

DESERT SANDSTONE¹⁸

Green¹⁹ has seen much more of the D[esert]. S[andstone]. than I have, as he not only worked over[?] most of the border[?] of the Opal Sea²⁰ for water supply information, but has seen the greater part of the outlying masses in Aust[ralia]. Asiatica which were called D[esert]. S[andstone]. and has settled their age by fossil ^{and geological 23} evidence. He is a thoroughly competent field geologist (I trained him! He is one of two only I found with the gift of an eye for a country) and not a mere specimen-hunting, section-slicer. I detest these office-bred[?] geologists! One beauty, a DSc.²¹ of Sydney has just done a paper on the structure of the Darling Downs²² which is about as like it as it is of ^to the Surrey Downs²³. He puts in faults, vertical and tilted beds and even overthrusts²⁴ to fit in the specimens in his bag, where on the ground the greatest dip is under 2^o !!

So Green at my request is marking for you on the latest Geol[ogical] Map of Q[ueens]l[an]d. the results of his work. I think I shalll keep the original and send you a copy with some of my own notes, together with a map of Aust[ralia]. up to the latest date, which I am drawing for you. Gregory's map in his "Australasia"²⁵ is not only out of date tho' [sic] pub[lished]. in [18]96, but misleading as he had not the necessary knowledge. He is a very good man, an original thinker of large views, but a good deal of his Australian geology (e.g. his theory of the plutonic²⁶ origin of our artesian water) is milky flap-doodle²⁷. I do this because the key of the question is the local separation of the two Australias & this is your work not mine. I worked it out quite independently *(after reading your book years before I came here , as you know) on the ground, to test it, and tho'[sic] Gregory, Hedley²⁸ & heaps more scout[?] it, they don[']t know and I do, and will tomahawk it into their heads yet. I fight for you as well as myself. [Confound it, I haven[']t got onto the Sandstone yet!)

*Jack²⁹ saw the fact, but misinterpreted it in his Geol[ogy]. [of] Q[eens]l[an]d.

[3]^{30, 31}

3.³²

The Desert Sandstone has been a great puzzle: no discredit to the geologists who tackled it: they'd never seen anything like it: Australia was then a new, untouched land of incomprehensibilities. The bother has been that there are sandstones, largely unfossiliferous, which cap the [1 word illeg.] L[ate]. Cretaceous (or have done so)³³

Diagram Section³⁴

C₂ ^C2 U[pper]. Cretaceous [Desert Sandstone]. C₁ ^C1 L[ower]. Cretaceous [Rolling Downs Form[^atio]n ] N. P. Newer Palaeozoic [Permo-Carboniferous &c]. T. J. Sandstone of Trias-Jura age mistaken for Desert Sandstone. The ridge of the O. Paleo ^{O[ld]. Palaeozoic} represents the central position of the Aust[ralian]. Asiatica[?] [ E[ast]. Aust[ralia]. say S[outh]. of [the] C[entral]. York[e] pen^[insul]a ]³⁵. The section is purely diagramatic to show general structure & does not represent any locality. Real sections would be so complex as to obscure my point.³⁶

All over the central region ^{and much of the E[ast]. coastal region}. It is much weathered and fragmentary, but caps all the hills, and makes koppies³⁷ of them, and strews the floor of the plain with its tile-like, porcellanous shards. Typically it is a sandstone, white or pale yellow, grains rounded by water action. It passes into coarse sandstone and shingly conglomerate in places & sometimes contains [1 word illeg.] coal seams. Its essential character is siliceous, quartzose in fact, but strongly marked by the presence of colloidal silica (chalcedony, opal, &c). Silicified wood (as yet undetermined) is abundant in the opal fields Ferns³⁸ Gleichenia a sp[ecies]. seemingly identical with our English & Indian Cret[aceous]. sp[ecies]. and a Glossopteris³⁹ of all other things. This was never before known never [1 word illeg.] Carboniferous & led to some of our D[esert]. S[andstone]. being assigned to that age in N[orth]. Q[ueens]l[an]d. tho'[sic] the geology ought to have shown its utter impossibility. Then it turns up in the S[outh]. African & Indian Trias and last season

[Sudden squall of rain blotted this: must wait. The temp[erature] has gone down to 78℉. pretty suddenly, so it is quite chilly! Dont you envy me & long for sunshiny[?] lands?]

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4⁴⁰

one of our Field Nat[uralist]. members⁴¹ ( Mr. [1 word illeg] ) discovered Glossopteris⁴² in a quarry in Brisbane itself in the Jura-Trias (Ipswich) Beds[?]⁴³. Palaeontologists are most useful folk, but they are, alas, seldom geologists, and like all folk who spend their lives in chairs (University or cane-bottomed) they are always cock-sure they have the only reliable time-keeper on the market. True it is a good ticker — of a sort — but it is but a Waterbury.⁴⁴ after all, and geology is the only Chronometer⁴⁵: it is jewelled in many holes[?], the Palaeontological Waterbury only in one. So the Pal[aeontologist]s., who are very good pals when kept in their place, for years (since 1890) bullied poor Rands⁴⁶ who said he'd got Gloss[opteris]. from the D[esert]. S[andstone]. and almost suggested he'd got the D. T.[?] instead. Even D^r. Gregory (don[']t mistake him for my friend the late Sir A. C. G.⁴⁷ the explorer, who was an accurate observer) op. sit. p. 344.⁴⁸ says "it seems more probable that some deposits of Pal[aeological]. Age are included in the D[esert]. S[andstone]." This is not moonshine but Cimmerian darkness⁴⁹. Both Green⁵⁰and I, to say nothing of R. L. Jack⁵¹ & Gibb-Maitland⁵², know the district and know it is D[esert. S[andstone]. and nothing else. The place is on the Cape River Gold Fields⁵³ about lat[itude]. 19^o 30' long[ditude] 145^o 30', and there are no Carb[oniferous][?]. rocks within 30 miles. When we geologists find a fossil in a bed whose age we know, we simply say it is in the bed, and all the Austrian-bent-wood[?]⁵⁴ palaeontologists between say South Kensington and Sheol⁵⁵ may blaspheme to the contrary. Why, if we always listened to them our Q[ueens]l[an]d rivers and Bays are Triassic or Jurassic because we now out Ceratodus⁵⁶with our hook and Rowk[?]⁵⁷ out Trigonia⁵⁸ with a [1 word crossed out] spoon, and Moreton Bay⁵⁹ is Siberian because Lingula⁶⁰still lives in its leathery shell. Exit Glossopteris in the lime-light!

There is also a fair marine fauna, molluscan and crocodillian,⁶¹ but again palaeontologists have [1 word illeg.] us. But I must not [1 word illeg.] on this, not wanting to bore you with a treatise. So I'll go on with the D[esert].Sandstone].

Besides its colloidal silica the D[esert].S[andstone]. in places contains much iron, often leached out as ironstone, often leached up by capillarity. But this is common [1 word crossed out] to

Cimolosaurus. I have seen its vertebrae of precious opal!⁶²

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5⁶³

all our Mesozoic⁶⁴ & Tertiary⁶⁵beds. E.g. at my back gate I can pick up bean-big pellets of magnetite⁶⁶ with a magnet, and hematite⁶⁷ with[?] my fingers, which fairly strew the surface, and have been formed by our splendid sunshine giving the [1 word crossed out] ^air such a healthy thirst that it drinks up chalybeate water⁶⁸ from sun-up to sun-down. No wonder our air is so hea^lthy when it takes tonics so freely!

Also the D[esert]. S[andstone]. often contains beds of shale, clay and thin coal.

Tennison Wood⁶⁹ and others have sought to make the D[esert]. S[andstone]. and even the Hawkesbury Sandstone⁷⁰ [ Trias-Jura) of N[ew]. S[outh]. W[ales]. aeolian,⁷¹ just as Richtofen[sic] did the Chinese Loess.⁷²This again is [several words crossed out] of "the uncouth cell where brooding darkness spreads her jealous wings, and the night raven sings."⁷³ Neither the D[esert]. S[andstone]. nor the Loess have any similarity to wind-drift sand — and I say it, who know the deserts of Africa, Asia, Australia, to say nothing of sand-dunes on all the coasts of all the seven seas. The wind doesn't lay out sands in flat cakes, it banks them up against every obstacle. Vide⁷⁴ art illustrations.

[a diagram of On hillside, a Dune, Blown Sand and Sea and Lake Sand appears here]

How I'd like to write you on the loveliness of Sand dunes! How the sharp edge of a 100 footer is often knife-sharp, and how in gentle breezes the little grains come hurr^ying on, tickling your bare feet, not three inches above the surface — sail along in fact — and where on the lee side⁷⁵ the wind is loosed from their tiny siliceous skysails⁷⁶ they drop suddenly, as if shot! Oh, friend, I know my sand! My diagram (central) is far too blunt atop for many a sand-dune 20 fathoms deep on Moreton Island in our Bay,⁷⁷ where I have gone a-hunting for fossil lightning (fulgurites⁷⁸) which those same travelling dunes will keep on though^tfully covering up, lest unworthy hands rake the fused[?] — tubes old Vulcan⁷⁹ has discarded.

But I MUST get on with the Desert S[an]dst[one]. Yet I love babbling.

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6.⁸⁰

What I am striving to say is that most (probably all) of what was quite reasonably mapped as D[esert]. S[andstone]. on the East side of the back bone of Aust[ralia]. Asiatica turns out to be partly Jura-Trias, partly Tertiary, and so does some of the W[est]. flank. Thus all the Cape York⁸¹ pen[insula]. sandstone is Triassic, most of that to the south is Tertiary and you'll have a good map to show the real inwardness[?] of things. You see any flat [1 word illeg]. looks like D. S. till it is interrogated on the quiet. Sand grains, unlike stars, dont differ (much) in glory.

But the Tertiary pseudo D[esert].S[andstone]. is geologically determinable. It used to be thought that much of our Basalt was of Trias-Jura Age. Jack,⁸²for instance gives this sort of idea of the Darling downs:-

[a diagram of the Toowoomba Range⁸³ appears here]

Whereas I find this to be the fact:-

[another, different, diagram of the Toowoomba Range appears here]

a In both cases Trias-Jura (Ipswich).⁸⁴

The basalts are all late Tertiary and break-through the Jura-Trias, and are NOT contemporary. The J{ura]. T[riassic]. beds are not bent[?] at all, not 2^o. The basalts issued quietly from long fissures. Now as there are no contemporary J[ura].T[riassic]. basalts it follows that any bed overlying the basalts are not older than Tertiary. I may say there are extensive volc[anic]. rocks of T[rias].J[ura]. age but they are confined to the lower — generally the very lowest part of the system, and are acidic not basic rocks. Now the so-called D[esert]. S[andstone]. in S[outh].E[ast]. Q[ueens]l[an]d overlies the basalts. Again, the great mass marked D[esert].S[andstone]. forming the 'bay' in S[outh].Q[ueensland]. and north N[ew].S[outh].W[ales]. on the west of the dividing range, around lat[itude] 28^o-30^o and long[ditude] 148^o-151^o Green,⁸⁵ who has just returned from there, tells me is not like D[esert].S[andstone]. in that

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7.⁸⁶

it is felspathic⁸⁷ and ashy[?] and contains Marsupial bones! It is in fact Tertiary. He got Macropus titan⁸⁸ or something like it, not yet critically[?] examined. Now this somewhat narrows my Opal Sea, just where the narrowing ought to be.

As to the (D[esert].Sandstone]) on the east of the range , I see no reason why there should not have been Cretaceous bays, except that the coast-line was there most probably out at^on[?] the Barrier Reef. But there was too much so-called D[esert].S[andstone]. It would have cut up Aust[ralia]. Asiatica into a handfull of halfpenny islands, and this hurt my feelings. I can now claim it as a good-sized lump of dirt.

New Guinea Connection.⁸⁹

The determination of the Trias-Jura age of the sandstones of C[ape]. York pen[insul]^a. is most important. All our Jura-Trias [how one does thimble-rig⁹⁰ these doubled names, let me call the beds "Ipswich" and save my reputation for orthographic sanity] is freshwater. On the sketch I have put the two chief Ipswich [Text from this point runs around a diagram of Early Mesozoic Lakes] areas. Note that both these lake basins run out to the coast. There must have been land on their sea-ward side. I draw in red the least possible outline of the lakes, and the narrowest likely shore lines. I think N[ew].G[uinea]. must have been connected in these times, but I suppose you don[']t object. As to later Cainozoic⁹¹ times note this. No marine Tertiary crops out along the E[ast]. coast of Australia and plenty do on the S[outh]. coast. All the E[ast]. [Text returns to full page lines] coast is fringed at intervals, often in very long stretches (hundreds of miles) with quite late land surface plains and deposits. So too is the Gulf of Carpentaria,⁹² and the Gulf itself is only a submerged land plain. Here we have strong proof (are there really degrees in proof? or is proof like honesty all positive?) of land connection between A[ustralia]. and N[ew].G[uinea]. I can find none between A[ustralia]. and Timor, though I don[']t doubt its possibility, even its probablility. This is in further reply to your Timorous objection.

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8⁹⁴

[UNCONFORMITY in the SKERTCHLY-WALLACE SERIES]

I break off to say I have just had a letter from my friend Mr D.F. Denham,⁹⁵ Minister for Lands, saying he has sent you officially all Bailey's⁹⁶ works he could get hold of, including his Bot[any]. [of] Q[ueens]l[an]d. in 6 vol[ume]s.⁹⁷ & his New Guinea⁹⁸ notes. Hope they will be acceptable.]

Wallace's Line⁹⁹

I do believe in that line. I've seen it. I've followed it up to the Philippines. Now Lamb said of a methodist minister "Sir, the more I think of him the less I think of him."¹⁰⁰I don[']t say this of the Line, but I do say "The more I think of it the less I understand it. It proves too much and too little."

Why can[']t the critters get across now!¹⁰¹ At any rate why havent enough gone sea-buffung[?] to smudge out the line? They can do it: only they don[']t. Allow me to illustrate from personal experiences.

• Australian & New Guinea natives. The ethnographic line is as sharp as bad claret: it is razor edged. And the Papuans have boats. I can easily explain this, as Hedley¹⁰² has done. The barrier is not the salt-water but the sharp spear — the spear driven[?] with more than rifle-bullet force by the womera.¹⁰³ My friend Jack¹⁰⁴ had was trussed in the neck with one. The blacks attacked the camp at night and one spear went through a kerosine tin and two bags of rice. A Martini bullet¹⁰⁵ couldn[']t. Now tho'[sic] the Papuan has a bow and arrow it is a poor wobbly thing (I have used them often, or rather shot with them, they are no use, which is the point of the question) and ineffective as a weapon against man at 20 y[ar]ds, whereas the Australian womera-spear combination is ^as good as a rifle up to 80 yards, and most uncomfortable at 100. This is why no Mop-head ever has made a footing among the Womera-workers. Here we have a plain explanation.

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9.¹⁰⁶

[1 word illeg. and deleted] But no such explanation fits the case of the fauna and flora, butterflies have no bludgeons.

II. Abyssinian Card Pyrameis cardui.¹⁰⁷ Years agone, in my early palaeozoic time, I watched, outside Cairo, the rolly-polly fat sheikh in [1 word illeg. and deleted] charge of the holy carpet bound for Mecca, and saw a mighty multitude of pilgrims start at a signal, bound across the desert for the prophet's tomb and the black stone of the Kaaba.¹⁰⁸ And I knew their incentive.

A few month's later I was coming a-camel down from the plateau of Abyssinia onto the coastal plain in early morning under a dull sky. The plain was grassy and every blade quivered tho'[sic] there was no breeze. Dismounting I found nearly every stem bore a pupa of P[yrameis]. cardui, just on the point of emerging. The sun broke, so did the pupae, and the First Plague of Egypt¹⁰⁹ was repeated, for all the land was bathed in blood — the drippings of the chrysalids. Faint and feeble this host of Painted Ladies ascended the stalks and hung their limp draperies to dry, and in an hour or so they were fanning their new-gotten wings. They too were a pilgrim band, countless millions strong, awaiting the call to the new Exodus.¹¹⁰ In a few hours or so ^{less than two hours} they rose en masse — like the Arab host — and steadfastly flew north-westward, sea-ward, and bound for Europe ^{where they swarmed}, and they have been, as far as I know, common in England ever since.

But I don[']t know their incentive.

III. Queensland Euploea¹¹¹ migration.

I was once steaming[?] at about 10 knots [text from here runs to the right of the page, around a diagram]¹¹² up the N[orth]. Q[ueens]l[an]d. coast bound for Cairns, lat[itude]. 17^o. The wind was steady from the N[orth] E[ast], see sketch, we were going about N[orth]. W[est] but had to turn east-about to get round Cape Grafton into the bay. Going on deck soon after dawn I

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10^{113, 114}

found a pilgrimage of purple-robed Euploeas beating to windward, close hauled,¹¹⁵as if bound for New Guinea. They were flying low, not above 3 f[ee]t from the water, so I could not get one to determine the species. As a rule these flights extend to many feet in height — I have seen scores and estimate some at quite a hundred feet — but these lay low from stress of weather. They were evidently sore put to it, and in deadly earnest, for the sheltering land was not a mile off, and to wind ^lee ward, so they could have drifted ashore without effort. But they were outward bound and couldn[']t and wouldn[']t lie to while they could make headway at all.

They [1 word illeg and deleted] crowded up under our lee for shelter, literally spurting to keep pace with our 3/4 speed, yet often dropping astern from fatigue. Then we began to turn westerly. Now, thinks I, here is a chance to see if there is a real compelling force, a vis emigrationis¹¹⁶ for these butterflies have not been blown off the land but are working to windward in the teeth of the breeze, and if the impelling force is not predominant, those that are using the ship as a helping hand will follow us come with us round the Cape and soon be on a southerly course. Not one did.

Thirty fell exhausted into the waves, the dead-beats in this strange Marathon rain — but by far the greater number had got their second wind and kept on their N[orth]. East]. course as steadily as if they were carrying the Port Moresby¹¹⁷ mails. As we ran south up to the pier there was not a butterfly alongside.

I dont know the incentive.¹¹⁸

IV. The case of Pieris teutonia¹¹⁹ in S[outh]. Queensland. Here in S[outh]. Q[ueens]l[an]d. we have great flights of P[ieris]. teutoria = Belonia java[?]¹²⁰ every year, at intervals of a few days sometimes for weeks together in the summer months. They always fly

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11¹²¹

to the S[outh]. S[outh]. East]. ^{N[orth]. N[orth]. E[ast]}. that is coastwards. I expect they go to sea like their relations, but I have never¹²² been on the coast when they happened to be on trek. All butterflies do best against a wind, 'tis the principle of aeroplaning, and I notice they wait till the wind gets a little northerly[?] in it before striking camp. Unlike my Cardui's these [1 word illeg.] spotted Whites do not herd together as larvae, but are spread uniformly over the country. They gather together for the trip,¹²³ and prefer the two hours before sunset, for no reasonable living creature likes our burning noontide sun. They are rather dilletanti tourists than earnest pilgrims like Euploea, for they take short flights of a quarter of a mile or so, dally over every flowering bush, flirt, put on the gloves and spar, and generally seem to have a good time of it. Indeed they don[']t seem to have anything on their minds. But they have all learned the lesson of Gen[esis]. XIX.26.¹²⁴ and unlike Lot's wife of HCl ^{NaCl 129} proclivities, they never look back.

They may circle round in their dances, but like typhoons, they have a set path. They don[']t do the whole trip on the day of issue, but philander along for days, camping anywhere at night from a window ledge to a wattle. Then they play about in the mornings, hold the noonday quiet rest, and when the sun begins to throw long shadows westerly ^easterly they start for the Pacific coast.

I don[']t know the incentive.¹²⁵

V. The Borneo-Sulu Passage. From the E[ast]. coast of Borneo to the more charming volcanic islands of Sulu is a pleasant afternoon's trip in a good prau¹²⁶ with a fair wind. Butterflies often seem to be

This text is written vertically in the left margin of the page:

Please don[']t forget the Mammals came to Java in late Tertiary times & tho'[sic] Pithecanthropus¹²⁷ puts in an apearance NO MARSUPIAL does!! Good for me! Again Negative evidence selects the most important omission, just to tantalise. Eh!!! Au revoir: had 1.25 in[ches]. [of] rain while writing this, between 2.30 and 6, the first spot blotted a page. Out d-d -d spot "Shakespeare". ¹²⁸

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exhausted with it, and I have met them, sober but half-seas over, many a time. But they don[']t get there. Why?¹³¹

Now to come back to Wallace's Line. Why don[']t the things get across? They can fly it without turning[?] a scale or ruffling a feather. And they are always at it and never arrive¹³² — which puzzles me. If you say "My good soul, you hav[e]n[']t the check tally of every emigrant & immigrant". I reply and some do, at long intervals". I reply that if the flora and fauna be truly inidgenous, there has been time enough, unless (which even you dare not) cleaned up, wet polished and dry polished the land till it was as smooth and shiny as the top of a mahogany table in very late Tertiary times and so started afresh a few (geological) hours ago. Now do you begin to see why I say your very real and absolutely genuine line is too true.

By the way, it isn[']t food caused butterflies to migrate and it isn[']t climate.¹³³

I dare not begin a new sheet, but it is such a treat to talk to one one who thinks and who cant think, that I needs must chat. I hav[e]n[']t written such screeds for 20 years.

So please give all our kindest regards to "Willie and Violet"¹³⁴ and take your full share for your treasured self.

Yours most faithfully | Sydney B. J. Skertchly¹³⁵ [signature]

Dont think I have exhausted my experience on migrations. I reek with them.

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13¹³⁶

P.S. Man prooposes but geology disposes and I find I must send you a couple of notes, forte notes too, though I'll try and make them at least semi-breve. I owe the facts to Green¹³⁷ and they are not published.

VI. The Barclay ^Barkly Plateau. Around the Q[ueens]l[an]d. and N[orthern] Territory border between lat[itude]. 18-20^o. ¹³⁸

[A diagram of the Barkly Tableland is inserted here.¹³⁹]

Section across Barkly's Tableland, N[orth] Q[ueens]l[an]d.

after L.C. Green

T.L. Tertiary Limestone

P.T.L. Post-tertiary Limestone, containing Isodora[?], Helix¹⁴⁰ &c. No mammals found.

P.T.L₁ Normal lie of Limestone, over the edge of which streams cascade.

Height of cliff 400-600'.

P.T.L₂ Limestone upended owing to faulting. P.T.L₃ Normal again.

D. Rocks of probable Devonian¹⁴¹ age.

D_1. Dense[?] Red Sandstones

D₂ Almost Quartzite¹⁴²

D₃ Claystones,¹⁴³ i.e. not fissile,¹⁴⁴ with small septaria¹⁴⁵in bedding planes. At X contorted by the fault. Underlying beds not shown visible on the ground being covered with waste.

NOTE. The PTL is shown (for the first time) on the map I am preparing. The Geol[ogical]. Surv[ey]. put it on at Green's solicitation.

First as to orthography. See how I hesitated above bet[ween]. Barclay and Barkly. I altered my first spelling to suit Green's notes[?]. But I find on the map Barclay Tableland, Barclay Downs and the station of that name is on Barclay R[oad]. But now you know how it is you can spell it with a [1 word illeg.], my lord. I don[']t want to describe this interesting post-tertiary plateau which is at least 150-120 miles in area except to point

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out the great extent of our cainozoic¹⁴⁸ strata and to illustrate crustal movements of at least 600 f[ee]t in pretty recent times. Also, the extreme interest of these beds as being on the eastern edge of Australia vera. The fault line which forms the E[astern] boundary of the plateau runs nearly E and W N and S. It forms a perpendicular cliff along which one may ride for miles before finding a way up or down. No mammals yet found in the limestone. It would be most interesting to explore the plain but I hav[e]n[']t got the cash to do it, or I'd be off pretty soon. It would take me as long to get there as to reach Wimborne:¹⁴⁹ distances are splendid here. I guess (Anglicé[?] non Americanice[?]) your curious limestone mentioned in the delightful "We of the Never Never"¹⁵⁰ in the Gulf country about lat[itude]. 15^o. long[itude] 133^o is of the same age.

VII. Obliteration of Strata by Planing Action of Rivers.¹⁵¹

You and I believe much, nay nearly all, the Cretaceous beds on the southern border of the Opal Sea in S[outh]. Australia has been removed by denudation. It is certain that the few patches remaining are very thin and the granite is now close to the surface. Green has given me a most interesting account of his observations in a region of [1 word illeg.and crossed out] similar conditions — the Barwan[sic] basin¹⁵² on our N[ew]. S[outh]. W[ales]. border.

[a diagram showing a section across the Barwan[sic] Valley is inserted here in the text]

Section across the Barwan[sic] Valley. (Diagramatic)

L.C. Green.

Length of section about 150 miles. Vert[ical]. scale exaggerated.

vv Alluvium of Barwal[sic]

S. The so-called Desert S[and]dst[one]. wh[ich]. Green believes to be tertiary.

G. Granite.

Central Australia as a whole is so worn down that the rivers have little or no power to remove save a small portion of the waste material

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15^153,154

due to atmospheric denudation, and few have now any appreciable denuding power of their own. This is also true of the great plateau of Aust[ralia]. Vera. The central plains, the bed of the Opal Sea, are just as flat, and it is to these that Green's remarks apply.

I have some passing knowledge of the vagaries of large rivers. My friend the Mississippi¹⁵⁵ I am aware will remove, sans warning, with all goods and chattels, not only from a township but a State avoiding, as I presume, so the phase of local politics. Another familiar friend the Hwang-ho¹⁵⁶ is the terror of map-makers. He (literally) slops round whole provinces quicker than a new edition of the map of China can be got off. But for all this waywardness you do know the Father of Waters or the Sorrow of China when you see him. But this is not the case with many of your Aust[ralian]. rivers. The very, very vulgar song ' 'E dunno where 'e are'¹⁵⁷ might be the lament or coronach¹⁵⁸ of many an Australian river that makes a big show on a map (or in an examination paper). Know ye the true origin of the term 'bed of a river'? Well, in 'going bush' when all the landscpe turns to amethyst and ruby and gold you look out for the smoothest and driest place inside the horizon and sleep there: it is the bed of a river! Half the year the "stream" flows 0 knots an hour, and the water, confined to placid water holes is as still as the water in a basin. See origin of another geographic change.^term All through 'the dry' the wind, which bloweth where it listeth, is engaged in picking up the loose sand from one place and popping it down again at random somewhere, anywhere, else. Then comes 'the wet' and the rains tumble down in a hurry as if Australia were afire and had to be put out instantly. What can a poor river do? It runs anywhere. There is nothing to stop it in the way of banks, and so you get a whole seies of more or less parallel, more or less temporary, channels or anabranches.¹⁵⁹ The poor thing can[']t cut any deeper — there is no fall, no head — so it planes away sideways, and shaves

[16]

16¹⁶⁰

off the beds.

Notice how the Barwan[sic] (see sketch) has sawed away both the Triassic and the (Tertiary) Sandstone. Remember it was once as high up as the highest Trias on the right of the section, and the Trias has once covered much more of the old rocks than it now does. Note, too, how the s[an]dst[one]. and the Trias are " feather-edged' away entirely to the left. It is a very beautiful illustration, and comforting withal. You and I may sleep in peace now knowing how it is the southern mouth of the Opal Sea has been obliterated.

Most of the sawdust of the rocks is blown about W[estern]. and C[entral]. Australia and covers the western plateau and most of the central plains with a beastly mess that hides the geology and gets into ones eyes, ears and vittles! And over most of Aust[ralia]. Vera this has been going on since Carboniferous times.¹⁶¹ Say hold on this dust of ages: [1 word deleted] fling it in my abandoned face, and cry aloud "Here IS my Negative Evidence, ground to powder: here IS my IMPERFECTION OF THE GEOLOGICAL RECORD pounded into unnameable fragments". But tell me when you recover your breath why it had a selective power over the corpses of defunct marsupials and over no other backboned or spine-less thing that had life. Gander and Goose, whose sauce is it: Thine O_, G or Mine the G!¹⁶²

Really I must, like my Australian rivers, dry up. Thou art my big teacher so I bully thee. No other man has so helped me, so I cheek thee. Quite one hip and thigh and I'll turn my other cheeks (I have as many cheeks as a dragonfly's eye has facets¹⁶³) to thee also — with thankful gratitude

Thine, dear friend Wallace | Sydney B.J. Skertchly [signature]