THE MINES STATEMENT.

Otago Daily Times, Issue 10193, 30 October 1894, Page 3

THE MINES STATEMENT.

(Fbom Odk Own Cobbesfondeht.)

Wellington, October 3. From the Mines statement of the Hon. A. J. Cadman I take the following:— MINERAL PRODUCTION. It will be found that the quantity and value of gold and silver produced for the year ending the 3lst December 1893 was 259,5870z, of the value of £922,881, while 700,693 tons of other minerals (including 8317 tons of kauri gum), of the total 1 value of £809,7«3, were also produced for the same period; as against 2R0,1320z of sold and silver, of the value of £958,740, and 687,295 tons of other minerals (including kauri gum) of a value of £907,566, produced for the previous year. The details of the quantities and values of the different minerals exported for the year are as follows :— Gold, 226,8110z, of the value of £913,138; silver, 63,0760z, of the value of £9743 ; antimony ore 331 tons, of the value of £3167; manganese ore, 319 tons, of the value of £943; mixed minerals, 37 tons, of the value of £858; coal, 69.138 tons, of the value of £72,699; coke, 51 tons, of the value of £53; kanri gum, 8317 tons, of the value of £510,775; while the coal produced and consumed in the colony amounted to 622,412 tons, valued at £311,206, making a total value of all minerals of £1,822,674. The value of gold and silver produced up to the end of 1893 was ,£49,454,886, and the values of other minerals and metalliferous ores, including kauri gum, are as "follow £17,866; chrome, £37,367; antimony, £49,507; manganese, £5f>,107; hematite, £226; mixed minerals, £70,322; kauri gum, £6,860,186; coal exported, £659,882; coke exported, £23,643; the value of coal raised and consumed in the colony being £3,542,408, making a total value of £61,072,410. The quantity of foreign coal imported for the year ending the 31st December 1893 was 117,444 tons, of the value of £111,950. Of this 6026 tons, of the value of £6460, was, however, again sent out of the colony. The yield of gold for the year ending the 31st March last shows an increase over the previous year of 12,0430z, representing a value of £52,753. The total yield last year, according to the customs returns of the quantity entered for exportation, not including the gold manufactured into jewellery, Ac, in the colony was 247,7020z, representing a value of £970,220, while the yield for the former year amounted to 228,6590z, having a value of £917,467. The increased yield last year came from the Auckland and Otago districts, being 11,3740z and 47810z respectively, while the Marlborough district showed a decrease in the yield over the former year of 7330z, Nelson 6130z, and the West Coast 27060z, making the total increase in the North Island and Otago 16,1550z and the total decrease in the other districts 41120z. Of the gold produced last year the Auckland district contributed 52,4260z, or 2178 per cent, of the total yield; Marlborough and Nelson, 44410z, or l'S4per cent.; the West Coast, 95,9300z, or 41*10 per cent.; and Otago, 84,9050z, or 35-28 per cent. QUARTZ WORKINGS. The returns furnished by the proprietors of crushing mills, which will be found in detail in pages 33 to 85 of the inspecting engineer's report on the goldfields, will show that this branch of gold mining is steadily progressing, and the yield increasing. As the quartzworkings may be termed " the permanent gold producing mines " of the colony, it is gratifying to findiihe yield of gold increasing from this source. The returns referred to show that in the Auckland district 89,916 tons of quartz were crushed and 18,900 tons of tailings treated, which gave 54,3850z of gold and 61,3890z of bullion, representing an estimated value of £219,651. This would be equivalent to about 55,2020z gold. The average value of the gold found in the Middle Island is about £3 19a per oz. In the Kelson district 4561 tons of quartz yielded 9140z of cold, having an estimated value of £3610. On the We3t Coast 45,090 tons of quartz yielded 5573J0z of gold, representing an estimated value of £22,015, making a total of 168,190 tons of quartz and tailings crushed, which yielded 120,2530z, of an approximate value of £359,490, as against £320,282 for the previous year. This shows that about 37£ per cent, of the value of the gold obtained last year came from auriferous lodes. In connection with quartz workings, I may observe that the improvements in the appliances for recovering the gold from the crushed pulp have had a great deal to do with the increased yield from the North Island last year. In some cases nearly as much gold has been recovered from the tailings as from the crushed ore after passing through the ordinary process of gold saving. This is entirely due to the introduction of the cyanide process. AUKIPEEOUS CENTRAL OTAGO. There ha 3 been laid before Parliament a scries of exhaustive and valuable reports upon the older auriferous drifts of Central Otago, by Alexander M'Kay, F.G S., mining geologist. The reports are admirably illußtrated with a geological map of the Otago goldfields and sheets of sketch sections. Mr M'Kay concludes his report as follows:—" A perusal of the foregoing parts of this report will show that, with respect to the older breccia conglomerate beds, these are not confined to the neighbourhood of Gabriel's Gully, Wetherstones, and Waitahuna; that they may be looked for and prove auriferous alonß the lower hill slopes to the south-east along the borders of the Tokomairiro plain, and over parts of the Kaitangata coalfield where the lower beds of the cretaceous tertiary series are exposed. Also, as has been shown there is a lar^e development of the same beds in the Horse Range from the downs on the southwest side of the range to south peak north-east of the gorge of Trotter a Creek. The same beds also appear in Mount Vulcan on the north side of the Shag river at its mouth. At Blue Spur, Wetherstones, and Waitahuna the beds are known to be auriferous, and also in the Horse Range. They should be prospected wherever prospecting can be carried on at a moderate cost, since it can hardly be that the three localities which have beea worked are the only places where these beds are auriferous. With respect to the older quartz drifts, they have b^on the great source from which gold was set free to enrich the more modern gravels at a great number of places on the Otago goldfields. An endeavour has been made to make it clear that these beds have not their auriferous parts arranged like le.ids along an old riverbed, nor in fan-shaped deposits surh as might have accumulated at tlie mouths of rivers or lesser streams falling into a like. It has been ehown that the Kol'i is found in a particular stratum or Btrata. which, *s iv thu case of the Maerowhemia goldfields, extends over its entire area, or the gold may be more concentrated in particular areas of lesser extent, but still iv every case it has to be considered that we are dealing with a gold-bearing stratum which has to be prospected after the manner of a coal seam. When the beds are tilted so aa to stand at considerable er high angles and are not overlain by younser deposits, they can be easily prospected by trenching along the surface of the ground; and t-veu wbeu the dip is at moderate angles, aa in the Maerewheuua goldfields, the outcrop of the auriferous stratum is usually easily to be found. Further prospecting should be carried on in these beds iv t,be hilly country between Pigroot and Hyde, at Hstmiltons under the basaltic sheet, and along the line of outcropping drifts to the Suwburn, and along the different lines that appear round the borders of the Maniototo Basin, Idaburn, and Poolburn ; Valleys, and in the Mamiherikia Valley, and | wherever the beds are met with east of the ; llolyneux river. The newer quartz drifts and

breccia conglomerates of Tinker?, Drybread, and ' soire other places along tbe south-east base of the Dumten mountains should be further prospected in the same way. The great difficulty in tho way of the further development of alluvial minim* in Otago is tho scarcity of water and the difficulty of bringing an abundant supply on to any places where hydraulic oluiciug could be carried on profitably. The measure of the water available is, therefore, that which must determine the rate of progress and increase of this form of gold mining. In the district examined at Fullerton's, Hyde, Haniiltons, Blacks No. 3, St. Bathans, and several other places, very rich driving ground was met with iv the quartz drifts, but it waa never apparently rightly understood under what conditions the gold stratum had been deposited, and an a consequence prospecting by shafts in the deeper gronud was usually adopted when the gold-bearing stratum might have been followed at the surfsce. It is hoped that thia report has thrown some light on the subject, and that future prospecting will ba carried on for driving or sluicing ground, not by the costly method of deep shaft sinking, but by following the outcrop of the auriferous gravels where these have been proved, and by trenches cut across the belt of drift country where the gold-bearing stratum has not been determined. Of the newer qucirtz drifts and breccia conglomerates on Criffel face. Cardrona Vallay, much cannot as yet be said, but it is a field that is very well worth prospecting, since it may prove to be continuously auriferous from opposite the Cardrona township to the mouth of the valley near Mount Barker. Of the newer miocene or older pliocene conglomerates, locally known as ' magri bottom,' these may not at many places be rich in gold, but they are at the present timo being worked at several places, notably at Switzers, and indicate a source of gold that is practically inexhaustible. The old high level lake ter .ces at the Crown terrace, Arrowtown, Frenchman's, and Midrun, in the TTpper Clutha Valley, show that at similar levels at other locali ties like deposits of an auriferous character may be found." ! ALLUVIAL MINING. Alluvial mining is confined to the Middle Island and Stewart Island, but at the latter place there is Bcsrcely anyone working. About 62i per cent, of the gold produced last year came from the auriferous gravel drifts oftheWest Coast and Otago. Very little alluvial mining is carried on. however, in the strict sense of the term, the principal workings being hydraulic sluicing and dredging. The ground as it becomes poorer requires to be worked on different methods from that adopted in former yt-.ars, when only a pick, shovel, and tin dish were required to enable the miner to earn his livelihood. Water must now be made to do the work instead of manual labour. By having a good supply of water and plenty of dump for tailings, a grain and a-half of sold to the cubic yard of material can now be. made remunerative, and when the material can all be sent away without having to handle any boulders even less than that can bs made to pay Seeing, therefore, that water is so necessary an adjunct to working th« auriferous gravel drifts, more attention should be given to its conservation. Every site for a dam or reservoir should be set aside for this purpose. At the present time the whole of the streams that can be diverted are utilised by miners for a certain portion of the day, but sufficient provision is not made for storing up the night water and also flood water. If this were attended to both the West Coast and Otago fields would afford profitable employment to a far larger mining population than at present. The number of miners employed in alluvial mining is almost entirely limited to the quantity of water available. Very little of the ground contains sufficient gold to pay for driving the best portions of it out, and water is tho only factor that can be used to make such ground remunerative. EARNINGS. The total number of gold miners employed last year was 11,533 against 12,197 for the previous year. Their average earnings showed an increase, being £S3 19s 7d per annum, against £75 4s 5d for the preceding year. Taking the different districts with the number of miners employed in each, and the value of the gold obtained, the average earnings in each locality would be as follows :—Auckland £16113 a 7d, Marlbo'ough £36 5s KM, Nelson £38 Bs, West Coast £75 73 3d, and Otago £75 18s lid:' : • ■

The average number of men employed in coal mines last year was ISBS. and the averake wage waa £107 4s Sd, against 1693 men who, during the previous year, earned an average of jEII9 7s)d. The average output per man last yestr waa 36(5 tons, as against 400 tons for the previous year.