GEOLOGY OF THE GREY DISTRICT.

Nelson Examiner and New Zealand Chronicle, Volume XXX, Issue 6, 20 May 1871, Page 6

GEOLOGY OF THE GREY DISTRICT.

Letter 11. To the Editor op the ' Nelson Examinee.' Sir — Your papers of the 3rd and 4th instant respectively came duly to hand, and accept my thanks lor the same, as through them I soe that you not only received my communication favourably, but also that jou foster goodwill to science generally, and particularly to what directly concerns ourselves. As there is an error in my last, for which I have to blame myself, I should like ! the same to be rectified. A doubt also exists with regard to tho supply of iron on the coast, as well as some misconceptions respecting the railway from tho coal-mine to Cobden, which I should likewiso like to ccc dispelled; so, with jour permission, I shall first correct the error, then give a description of tho ferruginous deposits, and conclude with a few remarks on the extent, cost, and most eligible site for a railway. The error consists in that portion of my last where it sajs, " talcing the average of the range to be five miles inland," which should read, " taking the axis of the range as a line to be five miles inland." This imaginary lino would produce the number of miles of tho western slope of the range, as I did not include any of its inland slopes towards Moonlight and other rivers. With regard to the resource of iron on the coast, and its quality, I shall first enumerate where it exists in the tertiary drifts, and then where it is in situ. Taking a particular survey of the Seven-mile beach, iL cannot fail to attract attention when we sco the first hill rising from the flat, tho starting point of the succeeding bluffs, as Point Elizabeth is disconnected from it by a valley. This hill has at its bottom a strata of sand, from ten to twenty feet thick throughout, in which. seams of irou-eand, from the thickness of a finger to three feet, and even more, are deposited, evidently by oscillatory motion, as the present action, of the ocean does separate tho heavier ironsands from the silicious and garnet iferous sands. This bed of sand is overlaid by about sixty feet of marl, which in many places overliips the aand, and bo hides it from view. This mavl is not coneolidated, but is an outlayer, apparently of terminal origin, by being brought from the main body, which stretches from the Seven-mile- Creek to the River Grey in about an E.S.E. course, and deposited on the sand ; no stratification is perceptible. On top of this marl rests a thick stratum of auriferous boulder wash, which has been bored into with but slight result. It con-

tains a good quantity of iron-sand, but would not be remunerative for that alone were it not for the boulders of which I shall speak in due course. At the foot of this bill, facing the sea", as also the Seven-mile Creek, by sinking to various depths Beams of iron-sand intermixed with garnetiferous and silicious sands, are met with in abundance, just like iv tho hill, from tho thickness of a finger to several feet. Leaving the Seven mile basin, and going as far as tho Ten-mile beach, we find seams of iron-sand for about a mile — not so vast as in the former, but, if auything, purer, which arc broken off by the protrusion of the Ten-mile Bluff and the rising hills inland. Going along tho bluffs, •wherever there is a small inlet or flat, patches of black Band are mot with, of limited extent, perhaps at every 100 yards or more, until wo come to the Twelve and Fourteen-mile beaches. Here "we have scams from one to six feet of about the bost quality. Passing over to the Seventeenmilo Beach, we arrive at a pieco of grouud, about eleven by one aud a-half miles in extent, the "whole of which is intersected by seams of ironBand, in parts of silicate, so pure as to lit it for tho furnace. If thoso seams wore extracted and made into a sheet, I have no hesitation iv saying, that wo could cover the whole Middle Island •with a sheet of iron two inches thick. The same may be said of all tho beaches north where I have been, and, by what I hear, extends as far as Collingwood. The above is with regard to iron in the sands, but there is another, and not less noteworthy, feature, which will some day be solved to useful account — that is, those boulder-washes resting on those bluffs, from the Seven-mile to the Twelvemile Beach, which contain boulders from the size of a fist' to that of a monster pumpkin — differing from those boulders I Bhall have to mention existing in situ, by being hollow, and inside filled vith a white, yellow, brown, blue, or black powder, that would not; be taken for iron by many, but iv reality it ia the very best, in a sulphuretted state. It would not take me long to gather fifty tons of it on the Ten-mile Bluff. With the above, I finish the tertiary. Now I shall cite whore 1 found the ore" in situ. Immediately abovo tho coal seam on the Nine-milo Bluff are boulders of iron, what in some parts of England the miner calis "cat-head" stono. Regarding their por cenlage, I cannot speak at present. Apparently, the}' are of very high per centoge. In some parts of the series they are intermixed, like the boulder of a sea-beach, tho interstices being filled by sand, of which tho series is composed. Many iron miners in Europe have not got such abundance or facility as hero is shown on the faco of tho rock. Further north, between tho Ten-milo and Twelvo-mile Beaches, where tho strata so often vary, red and black seams of sandstone crop out from six inches to several feet thick. O<i examining the same, I found that the strata were cemented into a solid cake by tho oxide of iron, which give the rock the black s and red appearance; and by pounding a handful, and washing it in v pan, nearly half of it in iron crystals — or, more properly speaking, prisms of iron ore, was retained. Tho abovo wero the only instances iv which I found abundance of iron in silu, but have no doubt that, by closer examination, other seams will be found. I cannot lay any claim to having pointed out their full extent or wealth, but simply that we need not be in doubt of a good Biipply. The differences in colour and weight of the Band-seams are explained by their different compositions, sonic of the laj-ers aro deeply impregnated with garnet eand, others with quarrz and other silicious sands. The garnet sand, as well as the pyrites, arc chiefly derived from granite, in which I have had the opportunity of Beeing them both blended together, but have now no Bpeciiuena at my command. In such cases where they are not separated tho seam has a reddish hue, mid by " panning off," as the miners term it, great difficulty is sometimes found to separato them. Other seams have a grciifc supply of silicious sands intermixed, in •which ease the seams appear greyish. Others have a dull black appearance, in which case they are pretty free of intermixture, but not of a high quality. Tho best are those of a bluish sparkling nature, which aro not so vast as the former, hub contain little or no mixture, and aro of greater specific weight. Although the iron-sands on the coast are not bo vast and pure a3 by report they are at Taranaki, yefc when we consider the coal as a fuel, and lime as a flux, at our hand, tho latter may fairly be considered to counterbalance the quantity and quulity of tho former. With regard to extraction, at present the gold miner has paid all his attention to. the best mode of extracting the gold from the siind in which it is minutely distributed, but if there were any inducement for turning the sand to account it would nofc bo long beforo the miner would have appliances by which he would first save the gold, and at the same time save the iron-sand from again being mixed on tho beach with the other sands, in fact, if he could get any remuneration at all for iron, seauis that will not pay him now for gold would then bo "wrought to advantage. Not being in the possession of sufficient data to give their respective weight and per ccntnge, I shall leave them at the present, but shall give you any result I may arrive at if time permits. I now take the liberty of making some remarks as to a railway from tho port to the Brunner coal-miuo. There is much talk just now about railways, tramways, &c. Greymouth "wants a railway, tramway, coal-mine, and what not ; estimates are being made, among them is one of £20,000. The other day I heard of one individual who proffered to make a railway from Greymouth to the coal gorge for the sum of £8,000. Now it is quite ridiculous to think Buch a sum to bo sufficient for seven miles and a half of line, when tho first milo out of Greymouth will nearly, if not wholly, swallow up one-eighth of that amount for forming, in addition to tho cost of sleepers, rails, rolling-stock, etatione, aud bridges, not mentioning any exca-

vations and corduroy. Decidedly a great deal of labour can be done for little money, especially on the truck system, still there has to be material. There is also talk of the most advantageous cite for the line. Some say tho Greymouth aide, others tho Cobden side. I coincide with the latter for tho following reasons : — 1. The distance from Cobden to the coal-mine is only five and half miles, while on the south side it is seven and a half miles. 2. There is not at present, and will not be without great outlay, any productive mine on tho south side, while there is one on the north side. 3. If a lino ou the north side be carried eight miles further, ifc will have the chance of opening another mine, while if on the south side, they need not expect any coal higher than the gorge. 4. If a lino were to be mado for produce or merchandize traffic, one side would have as good a chance as the other. 5. That Gtreymouth and its wharf, is no greater security to any company thau Cobden and its wooden wharf is. 6. That the line from Cobden to the coal gorge could be made cheaper than that from Greymouth to the same point ; and, lastly, that if no harbour is made at Point Elizabeth, a good stone wharf can be made at Cobden much cheaper than at Grreytnouth t owing to a quantity of suitable stone lying close to the site, the removal of which would also improve and deepen the tideway. The above having regard to advantage, I shall now givo an opinion regarding tho coat of construction. I would not dream of making a permanent line from Cobden to tho coal mine for £8,000, but would give the best part of £30,000 ; for if any company were to send a competent engineer to inspect the country, ho would either come to the conclusion that misstatements had been made, or that those who gave out. such an idea had no idea at all. The subjoined figures will give my estimate of cost. It may be high, still I know 1 could not make a grosser mistake than estimating it at £8,000: — For clearing and forming 5£ miles, £ ». d. at an average depth of 3* feet . 12,000 0 0 For 6awn sleepers for same . 2,000 0 0 „ bridgo across Coal Creek . I,'JOo 0 0 „ „ „ Sulky Gully . 200 0 0 „ station at Cobden . . 1,500 0 0 „ station ufc the mine . . 750 0 0 Total .... £17,430 0 0 which, taken from £30,000, leaves a balance of £12,550, out of which sum 21,296 yards of rails have to be bought, rolling-stock, and turn tables, which, if bought in the best market, and shipped to the Coast, when landed will leavo little of my estimate. Now, I don't see the least chance how a permanent line could bo made on tho south side, even for that sum. If a company were to make their own rails in their own foundry, perhaps a great saving might be effected ; but not vene £20,000 would be too much for a good foundry. But we will have to wait till perhaps some English or American company will smelt iron here. Hoping I have nofc intruded too much on your space and patience, I am, &c, Grey Valley, April 22. Advance.

FliENcn Cukese.— The Agricultural Gazette has the following : — "The cheese manufactured in the old provinces of Bresse, now the department of Am, is made by boiling the milk, adding a little saffron, tuking it oil' the fire, and putting it in the rennet immediately. The curd is then dried in a cloth, pressed for a few hours, put in a cellar, and salted five or six days after, this little operation being continued for a month. Auvergne or Cantal cheese is made without boiling the milk, but curdling ifc while fresh from the cow ; the whey being then separated, a man with his legs bare up to the thighs, gets upon the table on which (he curds have been put in a tub pierced with holes, and kneads the puste thoroughly with his arms and legs; p.n operation which lasts about an hour and a half. Tlie uniform mass thus obtained is left to ferment for 48 hours, and then salted, put inlo moulds, and pressed for 21 hours ; after which the cheeses tiro put in a cellar, frequently looked after and rubbed with a cloth dipped in fresh water. The celebrated Koquefort cheese, made in the village of that name in tho Aveyron, is obtained with a mixture of shecps' and goats' milk ; but even in the milking there is a secret, for when the udder appears to yield no more, tho maid strikes it reportedly with the back of her hand, whereby a little more milk is obtained, much richer in butter. This operation, which is utterly harmless, causes the udders to inereaso in size in course of tiuv\ The next reason assigned for the peculiar flavour of Roquefort cheese is, that when made into cakes it is kept in caverns hollowed out in a calcareous kind of rock which skirts the village ; the temperatu'O of these recesses is kept low by various contrivance?, and seldom rises above 5 deg. Cent. The cheese is made with the milk in tho morning and of tho evening before. The other manipulations present no peculiarity; but as for the veins, or persille, a3 they are called, they are obtained by mixed crumbs of mouldy bread with tho curds. The quantify of till-* cheese annually supplied to thfl trade is 900,000 kilogrammes (of 21bs. each). Frontage de Brie ia chiefly manufactured in the depattmenta of Seino-et-Oise and Seine-ct-M-irne, to the amount of 2,500,000 kilogrammes per annum. Rennet is put into the milk while warm from tho udder ; the curds are mado into cokes and laid on wicker t^ays so that the whey may run off. After 2i hours they are Baited, »,nd then turned and shifted from time to time for the space of a fortnight, or three weeks. At tho flong Kong races, which took place on the lvt March, the best prizes were carried off by two Australian-bred horses. North Australian, a horso hailing from Queensland, won tho Portuguese Cup, a mile and a-qii'irter, the first day, carrying list. The second day he won the Challenge Cup, two miles, value 500 guineas, carrying lOstlllbs; and on the third day he ran second in the lfakei Cup. Birmingham, another Australian horse, won tho Hong Kong Cup, one mile and a-half, carrying lOst 4lbs, value £100; and the Fukei Cup, two miles aud a-half, carrying list. '