COAL IN THE MALVERN HILLS.
Mr. Gobley has kindly placed in our hands* for publication, the following letters, which he has received from Mr. Cridlaml and Mr. Lyon, relative to the coal found in the Mahern Hills. These documents will, we have no doubt, be perused with great interest by our readei-s. Lyttelton, January Y§th, 1852. Sin, —In compliance with your request, I examined, on the 16ih instant, the seam of Coal which has been discovered some time since in the bed of the river Selwyn by James Robinson Clough, the Stockman at Mr. Deans's Cattle Station : and I beg to lay before you the following sketch of its appearance and position. V The surface of the valley of the Selwyn is covered to a depth vaiyiug from 1 to 12 feet with a layer of boulders and gravel. The river has cleared a broad channel through this layer, down to die bed of rocks on which it rests, and which consists of the outcropping ends of a strata dipping to the southeast. These strata., where laid bare, appear to be composed of sandstones, shales, ironstones, clay slates, and grit stones of various composition, and degrees of hardness and thickness. .„..; The Coal strata occur among these, and appear in three separate parallel lines traversing the bed of the river obliquely. The seam which was first discovered by Clough is numbered 3 on the sketch plan, and sections forwarded herewith. This seam rises above the level of the water, near the south bank. The other parts of No. 3 and portions of No. 2 rise above the bed of the river, and together with the parts of No. 3 exposed above the level of the water, afford facilities tor measuring the dip as indicated in the margin. No. 3 is worn down to a level with the bed of the river. -^These three are the only appearances of Coal which have been hitherto observed to have been laid bare by the river, the greatest depth of which at this poiut is at tliis season of the year, not quite thiee feet. -•: During freshets the whole of the Coal is under water, iind cannot at such times be seen without difficulty. 4T'he outcrops of Coal traverse the river in straight lines running north-east and south-west, and must probably extend to the hills on either side of the valley, through which the river runs, and which is here about 2 miles wide, taken obliquely in the direction of 'he Coal seam. -Vfhe dip of the Coal formation, as measured on the surfaces exposed above the bed of the river is about 19 degrees towards the south-east, which nearly corresponds with the angle of the dip of s< me of the sandstone strata, which expose their propiles in a perpendicular part of the north bank of the river not far from the seam which bassets in the nver. The widths of the seams as measured in the bed of the river, are as follows, viz.:— No. 1 . . .11 Feet. • No. 2 . . .9 Feet. No. 3 . . .6 Feet. The spaces between the seams tinted black on the plan aud section, are covered with boulders, a partial removal of which at A and B an plan, shewed that No. 2 and 3 were much wider on the surface tL.in the above dimensions, and consequently that the seams were much thicker than indicated by the section ; and from the absence of the appearance of any shale in those spaces, but which is distinctly visible at C under No. 3, and at D overlapping No. 3, I think k it jstrongly probable that Kos. 1 and 2 will be found to form one single seam about 15 feet thick, and I do not think it all improbable that Nos. 1, 2, and 3 form but one seam about 35 feet thick, cropping out in three places. The probability that at least Nos. 2 and 3 foim but one seam is much strengthened by the size of some of the masses of coal which have been washed down by the river, and which are too large to have ever been embedded in either of the three seams separately, unless they are really of much greater dimensions than they appear to be. It is probable also that as these detached masses are much worn by the action of the current; they have been formerly larger then they now are. The sketch plan and sections of the Coal seams as they appear in the river bed appended hereto, will give a much better idea than any written description of their dimension and appearance. The specimens of Coal No. 1 and 2 which I forward herewith, were procured from seam No. 3, tin Coal of which is similar in every respect to that of Nos. 1 and 2.
The other .specimens numbered 4 and 5 were taken, the former from under the Coal at C, and the latter from over the Coal at D on pkn and section. I burnt some of the Coal from this formation; the pieces I used were portions of tbe specimens numbered 1 and 2, and some pieces washed down by the river, weighing altogether about 2 lbs. They were placed on a few embers of a wood fire on the ground in the open air,—the pieces of Coal became ignited immediately and began to flame in about five minutes ; they afterwards split into clear bright embers throwing out as much heat as a far greater bulk of the best wood fuel, and continuing to burn for upwards of two hours. The smell emitted by the burning of the Coal was not very powerful, and not by any means disagreeable ; it appeared to me to be slightly bituminous without the least trace of sulphur. lam not able to state what the residue was of the Coals I burnt myself, in consequence of a wood fire having been kindled over tbe spot, before I observed it; but the residue of a large coal-fire made by Messrs. Fitzgerald and Draper some time since on the dry bed of the river, very near the Coal seams, consisted of hard, blackish cinders, mixed with grey ashes, a reddish tinge appearing here and there. S With regard to the accessibility of the Coal; a cart from Christehurch can approach at present to within half a mile of it ; an outlay of £5 would enable it to come close up to the spot. "■-,.; By laying out a direct route, and an outlay of £500 expended in forming crossing places in the steep banks of the river Hawkins, and a fe%v other old water courses, and the formation of a good well of water about half way from Christehurch, a loaded waggon would he able to perform the journey to and from in three days. With regard to the best method of fairly testing the quality of the coal, and of ascertaining the easiest mode of working it, I recommend that a shaft should be sunk at a short distance from the edge of the river bank, as indicated in the sket.-hes, and carried down to the under surface of No. 1. By this method, fair samples of .he Coal which have not suffered by exposure to the water and atmosphere would be obtained, the depth and dip of the bed woull be clearly ascertained, and (what I should consider of great importance) some of the geological characteristics of the formation would most probably be brought to light. At the same time, the extent and direction of this and any other formation which may exist, should be carefully explored in the valley and hills on both sides of the river, with the assistance of borings where necessary and practicable. own impressions of the quality of this Coal are, that it is very far superior to any other which I have seen or heard of in New Zealand, and considering that the samples tried have been procured from the surface, where they have most probably been exposed to deterioration for centuries ; there is every reason to believe that when the seam has been penetrated, and proper samples procured, it will be found to stand a very fair comparison with the best Australian Coals. I have the honour to be, Sir, Your obedient Servant, H. J. CIUDLAND.
Lyttelton, Feb. 16, 1852. Sir, —In furtherance of your desiie to have tha coat deposits in the valley of the Selwyn explored, I proceeded on the 25th ult., with a party of five men, to put in operation the proposal mentioned in my letter of the 19th ult., for testing the quality of the coal, and the easiest mode of working it. Owing to unexpected delays, I was not able to commence operations until Monday, the 2nd February, with a working party of five men, provided with the implements and material necessary for sinking a 30 ft. shaft through the seam<. The following day I discovered that I should have greater difficulty than I had anticipated, and was prepared to meet, in excluding the water from the shaft. 1 therefore abandoned my first intention ; and in order to attain the same object with the means at my disposal, I took advantage of a rapid in the bed of the river, a shcrt distance from the coal seams, to open a trench nearly parallel with the river bank, and discharging into the river below the rapid with a uniform inclination upwards from the foot of the rapid to ihe level of the river bed above tbe coal seams. The bottom of this trench was below the basset of the coal seams in the river bed, and its object was to carry oft the water, leaving dry the out crops of the coal seams : this would have enabled me to sink a small shaft through each of the seams. I discovered, however, that seams Nos. 1 and 2, where traversed by the trench, were below the level at which they cropped out in the bed of the river. I found that seam No. 3 rose above that level, but the period during which I was limited by your instructions to retain the working party, did not allow of my attempting to drive a shaft .through. I therefore caused a portion of the lower edge of this seam to be blasted out, the shot being at a depth of two feet. The quantity of powder used was about four ounces, tie quantity of coal reduced
to a condition fit for removal, was about three tons, in masses of a cubical shape, varying in hulk from one to three cubic feet, the quantity of slack being very small. On further observations I discovered that the j three seams rose higher in the north bank, and I i procured coals from Nos. 1 and 2 without difficulty j in this position. In the excavation of tbe trench on the bank of the river, I discovered several smaller teams of coal, overlying and interstratified with the seams Nos. 1, 2, and 3. It also appeared that Nos. 1 and 2 were not united in one as I previously supposed, but that I had mistaken a black bituminous shale occupying the space between Nos. 1 and 2, for a continuation of the coal, and I also discovered that the same cause had led me to over-estimate the real thickness of these seams on my first inspection The accompanying sketch shews their corrected measurement. Above the shales which cover these seams, is a thick bed of soft white sandstone. The same deposit appears in a slip in the hills north of tbe river, and distant about half a mile from it. On searching at the base of this stratum, I discovered seams of coal; these, from their appearance, position, aud association with shales and strata similar to those which are associated with the seams in the river, lead to the conclusion that they form a continuation of the latter, and this impression was further confirmed by its being impossible to distinguish any difference in their combustion. The bed of soft srndstone which is upwards of 30 feet in thickness, is overlaid by a stratum of hard blue coloured limestone, upwards of 60 ft. thick, with shells embedded, and masses of argillacous limestone, sometimes of rounded form, coated with a hard calcareous spar. This limestone stratum crops out at a distance of about 80 yrards from the coal, and rises five or six feet above the bed of the river. I traced this stratum from i:s intersection with the river to the point of a low spur about a mile distant from its southern bank in aline parallel with the direction of tbe coal strata, and under it I subsequently discovered the stratum of soft white sandstone before mentioned as overlying the coal, and I conclude that if I had had available means of excavation at my disposal, I should have discovered another portion of the line of river seams. The limestone is of excellent qualities for building purposes. Following up tbe course of tbe river a distance of about two miles from tbe river seams, tbe north bar.k rises in a cliff about 100 feet high. The face of this presents a series of bands of sand and clay ironstone, divided by laminated shales containing thin seams of coal, which, though too thin for working, are generally of excellent burning quality. These strata are continued across the btd of the river, which they traverse in the manner shewn in the accompanying sketch. There are upwards of twenty bands of ironstone, some of which are sandy, they are not uniform in thickness, but vary between ten inches and two feet in thickness. Specimen No. 25 is from a clay ironstone band twenty inches in thickness. Specimen No. 26, are from "the thin coal seams at this point. About two miles from this cliff, tbe face of one of the offsets from the hills whi-;h form the northern boundary of the valley is denuded by a slip, and displays the basset edges of four seams of coal ; tbe forms and dimensions are shewn in the accompanying sketch and specimens, Nos. 31, 32, 33, and 34, are taken from them. The roal from these seams is very slow of combustion, and does not flame excepting when subjected to a powerful blast, or mixed with more inflammable fuel in i state of ignition. The residuum is a hard black ember with a metallic lustre, and a considerable proportion of grey ash. Several other seams crop out in slips among the hills, but as far as I have yet seen, they are mostly of very insignificant dimensions. It is probable, however, that many seams equal in quality, if not superior to the best of those discovered, are buried under the horizontal gravelly stratum which covers the valley, as masses of coal washed down by the river are discovered, which do not resemble in any particular the coal from any of the seams discovered, and the appearance of which is more analogous to that of English Newcastle coals. I have burned coal from all the seams which I have mentioned, and I prefer that from the river seam.--, and you are able from actual experiment to form an opinion of its merits as a fuel. A sufficient quantity has also been brought down and deposited in the Land Office at Christehurch, to enable, the public to judge for itself. For the purpose of ascertaining whether tbe coal was fit for smith's purposes, I have had samples from the river seams and from the four seams in the slip, tested by Mr. Anderson of Christehurch, who has pronounced them not well adapted for this use, from their not caking like English coal, and consequently not yielding a sufficient intense heat. The coal of these seams is also in the most accessible position, and no doubt the principal supply of fuel will be drawn from them for some time. The readiest mode for procuring coal for immediate purposes, would be by open workings, unco vering and excavating the six feet seam, following
it up from the north bank of the river towards the hills. The coal may be broken up by means of small charges of powder, set with eight or nine feet jumpers, and when raised, the cavity may be filled with stones and rubbish from the next forward portion of the seam to be blasted. The next most convenient method would be by open workings of tbe seams in the valley south of the river, this would require some preliminary, though not difficult operations in the way of surface drainage; the coal might be raised in the same manner as in the former case. The third would be, to cut a drift at so low a level as possible into the hill seam on the north bank of the river, and work up the seam with inclined galleries, which would provide for their own drainage. I have no doubt that each of these m-thods will be adopted, and that they will be found adequate to the wants of the settlement, and more compatible with its circumstances than mining operations of a more regular and scientific character. With regard to tbe best mode of supplying the settlers at Christchurch and its vicinity with coal, I assume that the object most desirable to be attained would be to bring this fuel into the market at a price so much below that of the very indifferent wood fuel at present in use, as to induce its universal consumption, and to avoid at the same time, the outlay of any large amount of capital, for which there would be from the limited number of consumers no prospect of an adequate return ; and I beg to lay before you the following suggestion, the consideration of which may, I hope, lead to some practical mode of carrying out so desirable an undertaking. I propose to excavate tbe coal by the Ist method mentioned above, either by employing hired labourers or by contract. To purchase waggons and horses, and to hire carters for the conveyance of the coal to Christehurch. I believe that light fourwheeled waggons carrying over two tons, are better for such a journey than carts, as, although there is greater frictiou, there would not be so much weight on the backs of the horses. The weight of a cart capable of carrying one ton, is about 9 cwt. ; that of such a waggon as I mean, would be about 14 cwt. A cart carrying one ton, would require two horses for tbe journey ; a waggon carrying two tons, would only require one additional horse. The journey there and back might be performed by a waggon with a team of three horses twice a week, the distance being about 30 miles. The cost of a waggon and team, if imported, would be as follows, viz. :— £. s. d. Three horses . . . 100 0 0 Waggon .... 33 0 0 Harness . . . . 20 0 0 £150 0 0 The cost of carriage for one week would be about as follows : — £. s. d. Keep of 3 horses, each 10s. . 1 10 0 Carter . . . . . 1 10 0 4 Tons of Coal at Pit, at ss. .10 0 Wear and tear of waggon, harness, I „ ,„ » shoeing, &c. . . . . j Interest at 10 per sent on £150 . 0 6 0 Share of Interest on sundry out-"\ lays, levelling line of route, sta- V 1 4 0 bles, &c. . . . . J Cost of 4 tons . .£6 0 0 Which is at the rate of 30s. per ton. A ton of English coal for domestic fuel is generally considered equal to 4 cords of tbe best firewood. 1 think, therefore, it may be safely assumed that a ton of the Selwyn coa1 would be equal at least to 3 cords of the fire-wood in use at Christehurch, which costs 30s. per cord, so that a very large margin is left in this estimate for profit. It is probable that a Village would speedily be formed in the neighbourhood of the coal workings, and that a half-way bouse and depot of provisions for the supply of the surrounding sheep and cattle statnns would be established, and the return loads of supplies to maintain these would materially reduce the cost of transport,' The expense of carriage would be still further reduced by running waggons on a tramway, but the cost of laying down a single line of wooden trams would be upwards of £30,000. It is scarcely necessary to add that if the introduction of coal could be effected in accordance with tbe plan suggested, this settlement would be supplied with cheaper and better fuel than any other in New Zealand. I have the honour to be Sir, your obedient Servant, (Signed) H. J. Crioland. To the Agent of the Canterbury Association. Riccarton, Feb. 23rd, 1852. Sir, —T have at your request visited the valley of the Selwyn, and inspected the series of coal deposits lately discovered there: whether considered in an economical or geological point of view, this discovery is of importance. Coal is_known to exist
in many parts of New Zealand, but the exact geological position, from the want of characteristic* fossils, has not been hitherto determined. I think it may now with confidence be asserted that the extensive coal fields of Ne-v Zealand are of cotemporaneous origin with, and the equivalent of the lower cardoniferous formation of English geologists. The Canterbury district from Timaru to Waipara, is in many places bordered by a series of lov/ undulating downs, resting on and lifted up upon the rugged transition rocks which form the vast boundary line of the settlement, it is in that portion of these downs known as the Malvern Hills, where the coal formation has been examined by Mr. Cridland, Mr. E. J. Wakefield, and myself. It consists of the usual series of limestones, sandstones, more or less indurate laminated clays, bituminous shales, seams of coal and clay, ironstone, which constitute what are called tbe coal measures. Tbe exact numbei of strata and their arrangement in a descending order, 1 have not been able to ascertain, I have, however counted upwards of 30. The line of hearing of all the strata appears to be nearly south-west and norm-east, having tbe slip to tbe south-east, with an angle of inclination of about 19 degrees. The limestone is tbe highest bed seen cropping out it is fossiliferous, of a superior quality, and at least 60 feet in thickness: separated from this by sandstone* and shales, lies the main seam of coal, the first in four feet thick, the second seam not far below it is 6 feet in thickness. These seams are of a superior kind to any New Zealand coal which I have yet seen the large seam is a compact black coal, witn a conchoidal fracture resembling the English channel coal easily lighted, burns with ]a bright flame, leaves very little residiuum, and appears to be free from the disagreeable sulphureous smell of the Nelson coal. Besides these seams there are several others varying from one to eighteen inches in thickness. The associated rocks contain several seams or bonds of clay ironstone, one of them abounding with freshwater shells of the genus uuio. The laminated clays and .shales contain impressions of leaves, stem* and ferns, many of the impressions of ferns are very perfect, and appear to belong tbe genera JPicopteris and Spenopieris. This coal formation will be found to extend alon» the back boundary line of the districts in a northeast direction, and I think will be found developed in great abundance to the north of the Waipara, I have traced and examined the same coal measure* nearly as far as the Hurunui River. From the north of Ko Motunau to the Waipara there occurs a very large deposit of white limestone, the geological position of which I have not been able to ascertain. A series of strata of the newer tertiary formation, sections of which are seen to great advanvantage in the bed of the Waipara, appear to be tilted upon it, it is immediately under this large deposit of white limestone, that the coal measures appear. Outliers of this tertiary formation will be found to cover the coal formation near to and on the flanks of Mount Grey, and perhaps over a great portion of the deposit. 1 have observed also that in some parts of the Malvern Hills, it is capped by a visicular lava passing into a volcanic grit. Without a series of extended observations.it is impossible to tell how far this formation may be interrupted by faults or slips, or whether the elevatory force whichjupheaved the enormous mass of volcanic rocks which jconstitute Banks' Peninsula, may not have affected and upheaved the eastern position. I think it highly favourable that many of the altered rocks which may be observed interstratified amongst the Felspather, Basaltic, and i'orpyretic locks of the peninsular, have formed part of this same coal formation. At Cass's Bay a fine yellow ripplemarked sandstone may be seen underlying tbe volcanic rocks ; sandstones and black shales crop out, or rather are thrown up on tbe hills in the rear of Gibbie's station. A careful examination of the southern slopes of the peninsula might be attended with some discovery, lam Sir, Yours respectfully, WILLIAM LYON. To J. R. Godley, Exq., Agent of the Canterbury Association.
Died.—On Tuesday night, February 24th, Jane Elizabeth, the infant daughter of Captain Simeon, aged three months. On the 26th instant, Mary, the infant daughter of Mr. R. Turnbull, Winchester Street.
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COAL IN THE MALVERN HILLS., Lyttelton Times, Volume II, Issue 60, 28 February 1852
COAL IN THE MALVERN HILLS. Lyttelton Times, Volume II, Issue 60, 28 February 1852
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