OUR GOLDFIELDS.

Auckland Star, Volume XXV, Issue 95, 21 April 1894, Page 2

OUR GOLDFIELDS.

DEEP QUARTZ JIIXIM>. THE VICTORIAN EXPERT'S REPORT. {El TELEGRAPH.-OWN" COEREHPOSDEM.) Wellington, this day. It will be remembered that in order to giv« an impetus to the mining industry in tbu colony, the Government invited tne victorian Government Geologist, Mr i.eginaw A- P. Murray, f.G.S., to visit New Zealand and report upon the prospects or paya&.o i eturns being obtained by working the.deep levels on tho Thames and other jroldfielde. Mr1 Jlnrray, in company wtth ~-r v. a. Gerdonj 0.E., F.G.S., I«Pe| tiDe f'»; gineer, and Mr A. McKay, I .U.S., Mining GebltJjtfsfc, visited the various fields and baa submitted a lengthy report full oi valuable information. The nrst group inspected waa the THAMES GOLDFIELDS. Mr Murray first refers to the valuable information given him by ilr James Park, #G.E, director of the ibames bchoot oi |.' Mines, Mr B. McDonald Scotc, Mr Gsorjro ~: Wilfidn, District Inspector of Slings, ana Messrs Duulop, Clarke, Smith aud Kaciford, mibe managers. . Mr Murray in his report states that too Tham&s GoldSeld is of volcanic origin, and its agts is about the Upper Secondary or Lower tertiary period. The rocks occur in tbrffS maib classes, which in the report are for conveyance numbered 4, 5, and 0. 80. 4 consists of hornoblonde andesites and tuffs, forming the " hard country " of tha mirier; the second (So. 5) of decomposed andesites and tulJs, forming the soft or " kindly country " of the miner, and often locally termed "sandstone"; the third (No. 6) of hard tuffs, andesitebreccias, and agglomerates, madetip principally of ejected volcanic fragments with occasional pieces of the underlying sedimentary elates. These slated, near the Thames, only outcrop over a email area ab Rocky Point, near Tararu, though they doubtless form the rock-foun-dation of the whole Capo Col'viila peninsula, as they outcrop at various localities. Leaving the elate outcrop ab Rocky Point, and coming along the coaat southerly towards tho Thames, the rocks as far as Kurunui Creek consist of the third-class, Kd. 6, Which have seldom, if ever, been found to contain auriferous reefs. From J£ururiui to Karaka Creek—about a mile — occur the andesites and tuffs (overlying, and your per than So. 6) ffi-which are described under Isos. 4 ,spd 5, and contain the gold-bear-■■"*jfptg reefa. These evidently extend southward tinder the newer sedimentary deposit? ifrhich form the surface from' Karaka Creak to Hape Creek, a farther distance of about three-quarters: of a mile. Near Hape Creek breccias reappear—whether No. 6 or not is nheertain ; bub there clearly exists between Kurunui and Hapo Creek.3 an area, nearly two miles wide, occupied by Nos. 4 and 5, which, from the surface to various depths, have been proved to be traversed by auriferou3-quartz reefs, and the deepest extent of which baa not yet been ascertained, while tho portion concealed by the itdfrdr sedimentary rocks is practically unprospected—i.e., Irom about Karaka Creek to Hape Creek. There h thus a basin or "channel in No. (i occupied by the auriferous andesites and tufTs (Nos. 4 and 3), the northern margin of which is represented by the outcrop of the noriatirifeYous breccias (No. 6) rising from bontiafch bear the Knrunui Creek. The auri- ■ ferous rocks' occupying thia ba3in also ap- : pear to shallow out upward in an easterly j direction, arid to deepen westerly or seawafd, while their southern margin i-i po far utadbteTmiued, being ohscured by i'ontertiary deposits. The aar.ifcroua-qaartz jre'ef4 anU veins traversing Nos, 4 and 5 fdrm 4 Vvi'de liiSlfc faaviDg a general direction 'nbffeß of 6asfc arid south of west. Tha quartz veins nearest to the north margin g'avfetSufc, as regards gold, afc comparatively eballow depths j but each succeeding refef or etOCkwork of veins southward haS proved gold-bearing to a greater and ' greater depth. This dip of the floor of the gold-Bearing; rocks ha 3 been noted as afeo'untibi* td 4621b in 37 chains by those cdbviereaftb with the workings. Fi om the Ku'tuuui to the Karaka Creek there are over thirty notable reofa and veins, apart frOm £h<J network or stockwork of veins i o6ttuffiiig bißtWtiisn them in many places, au'dh as tlid Shotbver ground, etc. These pfitibipai reefßi all to tho northward of a point botwoon tho Saxon and Queen of Bfeattby ehaffa underlio northward, while southward of that point ! thij, Majority 'of the reefs show a I BdUtheriy ihclihation and there appears nothing in the structure of the rocks to accoinifc for this, which, may, after all, bs a coincidence, though suggestive at first! glance of a " saddle " formation on a large ; gtfald. the rocks of this basin have boon Bubjecbed to at least two great dislocating ' mbviamei'uts. The great Woanataiari fault or slide has caused a downward slip of a large pbf'tioii of the r'octi3 towards tho aea, aria tne line of the fault is clearly traceahlo on the ground by the physical configuration of ths country, and by tho actual attritionmirks bh its ekpbsad wall-surfaces, while it is itlsd diStincb in such tunnels or drives as haYs r'edch'ed or cbtthrbugh it underground, j iTbo vertical displacement caused by tho fault has been estimated ab from 300 ft to 6&6(t, bU6 whatever it be, by so much lower . afe tne rd'eiks ahd their contained quart/retffe ori the coast aide of the fault than j tfteif equivalehta on the inland ?ide. : Another fault; known ac tha "Collarbone" acts iH & similar manner, but curves round and meets the Moanataiari fault to tho scSuth-west hear Karaka Creek, and whether the two intersect and continue in independent1 courses or coalesce in one is as ybt undetermined. Near tho coast line a beach elide has been cut, bub owing to the j nature Of the ground ife was considered unsafe to explore further seaward beyond this assumed fault', but, if it really bo one, it implies the existence beneath the gulf of a considerable section of rock, the downthrowri continuation and equivalent of tho exposed portion between the Moanataiari fault and the coast-line, in which the richest reefs and veins have hitherto been found. Going up the Waio- . tahi Creek and crossing the Moanataiari fault, the junction of two great reefe is ltibb with—the southern known as the Waiotahi, this hortherh as the Golden Age. Thß latiter reef in the Fame and Fortune m!nß ia 30fb in thickness in places, and, though auriferous, has nob been much worked, thg " droppers " or branch veins on either side yielding the principal gold. This reef is regarded by somo as the continuation of the main reef formerly worked in thta Caledonia ground with auch exceptionally rich results. Dixon's reef is about the most northerly line on the field, except Bdme detached workings of small extent to the northward, near the Tararu Creek, and Is accompanied on the hanging-wall nido by oho of the hard undecomposed aiidesite bands. This reef has been worked to as much as 10ft in thickness, arid, where joined by the Sons of Freedom line, was Very rich. The Orlando mine is on a ftfdf known variously as the Orlando, Bendigo and Reuben Parr; a tunnel here follotva a strong well-defified reef bearing north-hortheasb and nearly vertical, with leaders coining into it. It lias not here beeri worked underfoot, though stoped at deeper levels to the southwest. It is oxpedted in this tnnnol to meet the gold ehoob worked by the old BendigO Company some distance ahead. The Sdri9 of Freedom shows a similar reef, which was very good above, bub poorer below1. The Moanabaiari tunnel, 2,070fb long, passed through the Moana- <

I talari fault. On the seaward side of the {fault adjacent ground haa been worked j below the tunnel level, but on the inland i sl'.lu no payable gold has been yet disi covered so deup. Beyond the fault tha I tuniiC-1 passes into the hard breccias (No. 16), Lut towards the present extremity I eaters a rock of the softor aud more j"kirid;y:' description. The continuI anca of this tunnel would be a desir- ; u.ija: prospecting work, to winch i lurcher reference will be made hereafter. Tvs iiazelbank Aline comprises tho ground of the old Caledonia claim, so fabulously nch iv early timed. Tho ahaft ia u4'Jfc cieop, and the No. 1 or Caledonia lode, though continuous, haa ceased to be pa/ably auriferous where it passes into the okt Tookey ground. Work ia now being principally directed to " droppers " on the banging-wall side of No. 1 lode. In the Vvaiotahi -Mine there are several reefs, ana also a complete ramification of veins. Southward the Saxon thail of the May Queen Mine i* obouO 490i't deep to No. 5 level and the lodes appear to have been regular down to that level. The northern or No. 1 reef haa a northerly, and tho southern or No. 2 a southerly underlie ; i new reef joins No. 2, and the lino of junction pitches eastward. There are various oti.er veias and loaders, and the gold-bear-ing shoota are stated to be continuous under foot. Tho old Queen of the May shaft is about 424 ft deep to No. 3 level. Driving waa in progress on the lode, which ia faulted in places, and is intersected diagonally by another lode ; good gold being obtained along this inuneciion. The lodo is 3tated to have been as much a3 20ft thick in places, aud some of tho gold-shoots are described as pitching seaward and others inland. At the May Queen shaft;, to the north-east, the rich gold ia reported to have commenced at aboub 300ffc from the surface, and continued to 430 ft, the lodes being the same as those in the Queen of the May and tho Queen of Beauty workings. The Queen of Bsauty ehaffc ia 748fb deep to Sso. 11 level, and the same system of reefs waa worked from it as those in the May Queen mine. These were auriferous as far down as the working 3 extended, and a good large reef was left at the bottom. There waa a poor interval about No. 6 level, but the gold made again from No. 3 level downwards; the rock at bottom was the "kindly sandstone:; of the miners—decomposed andesito or tuff, ' Tho drives at tho 4Goft level extended seaward to tho so-called Beach fault. Una Hill, south of Karaka Creek, is traversed by a large low-grade reef known a3 the Hague-Smith line, and, in addition, there are numerouß auriferous btoekwork veins in the rocks on the southern and western slope*. These stock work reins are rather a feature on this field, as they frequently carry rich gold while the larger reefs are poor. The Skotover ground, and in fact mostof the area between the Kurunui and VVatotahi Creeks, i-j intersected by euch veins, in addition to the larger reefs. To describe in detail all the reef? of this field and their features would be a work of no ordinary magnitude, but ttio foregoing sketch i 3 sufficient for the purposes of tnis report. The question of most eerious momont at present is whether thyre 13 a fair chance of valuable developments being effected by means of deeper explorations, as most of tho easilyaccesaiblo 'luriferoua ground is exhausted, or rapidly becoming co, and the great difficulty attendant; on deep sinking ia the water, which would necessitate the erection of a powerful and costly pUtib before deeper sinking could bo attempted. No tingle company on the field appears to i; 9 aba to undertake the erection of the necessary plant, nor does it oven seem tbnt there ia che ability to effect it by combination of a greater number or the whole. Some assuirtnce of success is, at all events, needful before enterprise in this direction is likely to awaken, though I should imagine the information already possessed with respect to tha deeper shafts in the i south-western part of the field should afford raaaonable encouragement. It appears evident that in that locality the bottom of the soft andesites ai;d tufis has hot yet been ieaclied,and so far as fcheyextend downward so fur are auriferous reefs or veins iikely to occur. 1 have no hesitation in expressing t be opinion, based on personal observation and reliable information, that exhaustive coating by means of deep sinking is most advisable, and that tho expenditure on the necessary pumping appliances would be fuliy warranted by the general indications, and I would advise preliminary boring to ascertain whether the soft tufaceous rocks really do continue to any considerable dopbh below v/but has been reached ia the doepesc mines. If this prove to be the case, then deep sinking will bo amply justified, bub if, on the contrary, the hard breccias be shortly met with, due project of sinking will wear a loss promising aspect. As a locality for such boring the vicinity of the Queen of Beauty shaft is recommended, and, chould the result be favourable, that s-hafc, from its position and size, seems the most suitable to selecb for deeper sinking, providing it bo in proper condition. Mr Murray further recommends the continuance of the Moanataiari tunnel, aa this will afford a highway to, and the facilities lor prospecting, a largearea of likely ground, the upper portions of which were very rich. Aleothe prospecting of the country between Karaka and Jlape Creeks by sinking through tho Poat-tertiary deposits into the tufaceous rocks and then cross-driving in the latter. If a deep ehafb be sunk at or near the site of the Queen of Beanty shaft, exploring drives should be extended southward towards Hape Creek, and westward towards the gulf, as it is quite possible that the auriferous rocks may extend far under the sea and the recent accumulations in its bed, and. may be worked ab auch depths that no danger from influx of water need be apprehended. COROiJANJJEL. The rock .formation is tufaceoue, of volcanic origin, and about the same geological position as that; of the Thames. In the Kapanga xMine, the depth of which is 600 ft, there are two nearly parallel reefs about 60fb apart, having a general strike north and south, but somewhat sinuous, and an underlie to the west. The upper or western is the Kapanga, the lower and eastern Kcotty's Reef. The foot-wall of Scotby's and the hanging-wall of tbe Kapanga reefa are tolerably hard, the country between being of a softer character; the lodes occasionally split up and meet again and the goid-shoots are patchy and unequally distributed, {riving out quite suddenly ab a cro^scourse or change of country, or a deflection in strike or underlie. The portions having tbe normal north and south strike and the steepesb underlie are usually richer than those deviating in strike or having a lower rate of inclination. These two lodes are supposed to be separate portions of one, separated by a " horse " and likely to cbriie together at depth. So far there appears no sign of their dying out downwards, and their tracks are continuous longitudinally as far as followed, though very little exploration has been carried on in the way of driving along them in search of other other blocks of stone. The Tokatea workings show one largo reef and a great number of smaller veins. The large reef ia auriferous but poor, the bulk of the gold being contained in the Bmallor veins adjacent to it. In some of the upper workings on the easb side of Tokatea Hill thero are vertical veins intersecting flat or.es, and these are frequently very rich along the lines of junction. There is a certain analogy between this feature and that observable in aome of the quartz-mines of Ballarat Easb, in Victoria, where the intersections of flafc " spurs" of auartz by their vertical veins of pyrites(indicators)are sometimes exceedingly rich. The rock formations and other conditions of tho two

j ocalitiea are, however, very dissimilar. i Lower down Tokatea Itiil are thin crystal- ; Hue vertical quartz veine, which aro rich i where they are intersected by one another or by jjinta or bead?. Towards the foot of the bill is a low-level tunnel—inaccessible at the time of my vieit —which is stated to have passed through too tufaceous rock into a projection of subjacent slate of the Maitai or carboniferous series, and it is reported that a reef was followed down from the superincumbent tufaceoua rock into the slate ; that a winze was ,-unk on it from the tunnel j and good gold obtained, but that it was abandoned on accouut of the large influx of water. Mr VV. It. Argall, manager of the Kapunga mine, made inquiries concerning this, and wrote stating thaD he had learned that the depth of the winze in the slate was 35 feet at 1,500 feet in from the mouth of the tunnel ; that gold was visible in the bottorri of the winze when work was suspended, and was the continuation of a shoot worked the whole way down from the outcrop of the big reef on the bill. The absolute verification of thi3 statement would be most important, and eneotiraging to further exploration

KARANGAHAKE. At Karangahake, in the gorge of the Waitawheta Creek, a large reef is being worked from a tunnel near the creek-lovel. The rocka are very similar to those of the Thames, but rather harder. There is nothing visible militating against the probability of this resf continuing to great depths. WAJHI. The Waihi Reef, near Waihi, is one of great size and importance. ltd outcrop is on a hill composed of tufaceoue rock or decomposed andesite similar to that of the Thames, and 13 about 30ft in thickness, the whole being taken out by open anarrying for treatment at the mill. A large main shaft is being ?nnk near the bice of the hill, and baa been connected with An adit driven to the reef, which shows a thickness of from Bft to 45ft., with no eign 6t dying out; its bearing is north-easterly and its underlie south-easterly. The quartz is "ribbony" and jasperoid or agatiform in many places. The cyanide process, for which a large plant has been erected, appears to have proved highly successful in extracting the gold. The flat country around the hill is composed of a rhyolitetufa, a volcanic product here, more recent than and overlying the andesite, which slopes away under it. The quartz reef does not extend upwards into the rhyolite, which is evidently a newer formation, but has every appearance of continuing downward and longicudinaliy in the andesite. It would be worth while to prospect for the continuation of this reef in both directions by sinking through the rhyolite down into the andesite. WAIORONGOMAI. The rocks are volcanic products, andeeites, &c, like those of the Thames, but harder. Numerous rich patches of goldbearing quartz have been worked along the mountain side, but thpy have not been traced to any great depth. In the lowest tunnel two reefs have been cut—a large one but poor, and a smaller one, which was rich above but poor at the tnnnol-levol. The big reef has hard aodesitea on the outside wall, but beyond tho email reef tlie tunnel parses into eoft " kindly " tufaceous rock, which may possibly pass under foot, in which caee the roof, on intersecting it, '■ may again be found to contain payable ' gofd.

Mr Murray also reports at length upon tho other goldtielde in tho colony, and in his summary states: — "'As regards the fufcuro of deep quartz mining in.New Zealand, I must confess to feeling Jess confident than I would were the rocka more similar to those whorein quartz reefa have so successfully been worked to yreat depths in Australia, but at tho same time the evidences are such as to warrant mo in the recommendations with respect to tho fields ■ where ac present a feeling of uncertainty exists as to tho probability of success in deeper exploration:-. These recommendation?, brieily summarised, aro a* followg : —Thames goldfiold : [a) Boring in the vicinity of the Queen of Beauty shaft, and deep sinking should that boring show that rocks of favourable character continue downward; (6) extension of the Moanataiari tunnel ; (c) prospecting ground beneath Post tertiary deposits between Karaka arid Hape Creeks. In many of the mines visited there is sufficient visible inducemenbfco further working, andoperation3 inthatdirectionarein progress, butthroughoutall of them the following-up of" tracks" of reefß in search of other shoots than those already known is very advisable. There is one more eubJ2cfc on which a few remarks may be permissible, and that is the recklessness as to the future which seems to have prevailed during the dividend-paying times of the various mines. All the inquiries mado by me failed to elicib information as to a single instance where, during a prosperous period, there waa a reserve fund established for future dead-work, or where such dead-work was steadily kepb in progress during the working of rich blocks of stone. Ib would appear that in a large proportion of the mines the good quartz waa atoped oat from level to level, all the available proceeds beyond current expenses being divided and nothing kept in hand for any future works of an extensive or costly character. This system, or want of system, has been in past timeß, and I fear often still is, followed in the Australian quartz-mines ; and the sooner that mining directors and managers appreciate its ill effects the better. Assuming a mine to be dividend-paying, a moderate percentage deducted from the divisible profits would be missed by no one, and if placed to a reserve fund for future exploration, or directed immediately to dead-work, would tend to maintain confidence, and to prevent the subsequenb tooth-drawing process of extracting calls from shareholders during periods of depression.