REPORT ON THE GOLDFIELDS OF OTAGO.

Mount Ida Chronicle, Volume VI, Issue 325, 28 May 1875, Page 3

REPORT ON THE GOLDFIELDS OF OTAGO.

BT Q. H. V. ULRICH, ESQ., -F.0.8. iCotaintted from our latt.y ; BEEFS OF MACEAE's FLIT. To this locality-1 was kindly conducted by Mr. Warden Robinson, of Naseby. At the head of Macrae's Flat, there have been at one time several so-called reefs prospected and proved auriferous (Golden Bar Reef, Moonlight Reef, etc.), but according to : description, they seerned to have only formed bunches, or ?blows," between,the beds of the country, running out in strike and dip. The only reef on which some extensive workings have been carried on is the Duke of Edinburgh Reef, and about the history of this and the. old company who once worked it, I received every information from Mr.'A. Simpson, a former employe of the company. The reef, where exposed, in a small cutting •from a gully near the old main workings, is 3 ft. thick* strikes W. 20° 'JST., and dips northward at angle of 35° to 40°, lying between the beds of a rather soft blue phyllite that formsfthe country rock. The footwall, or underlying rock-bed, is well-defined and smooth, but the hanging, one is broken and traversed by small quartz leaders, dipping towards the reef, which latter is composed of about fifteen or/ eighteen inches of. quartz on the foot-wall, and nearly 2ft. traversed by qtiartz strings, on the hanging wall. The quartz is good-looking and abundantly impregnated with pyrites. As regards the old. workings, which consist of open cuttings and shafts, now more or less. coU lapsed, they extend, with a few- interruptions,, for 12 to 15 chains in length; but the greatest depth reached at any point was, according to Mr. Simpson, only 40ft. The quartz, which was principally selected for crushing, ran trom 10 to 18 inches in thickness, and paid from 7dwts. up to 2oz. of gold per ton. It was nowhere lost in depth. The such, is traceable for more than a mile in strike, and crosses .two small gullies, which, from the crossing line downward, have proved very rich in gold, a clcarproof that the denuded portion of the reef must have been richly auriferous also, and' indicating the chance of the latter being payable in depth. The company's crushing mill was a very good one, but, judging from the coarseness and pyritous nature of the tailings, and that, according to Mr. Simpson, a large quantity of quicksilver was lost, a great deal, of the"gold,^which was very fine, must have been lost also. On account of the scarcity of water in the locality, the company had a fine reservoir constructed inthe gully below the reef, from which an adit led the water to- a shaft, 50ft. deep, sunk close to the machine, and furnished with pumps for supplying the batteries. Considering the nature, extent, and auriferous character 'of this reef, and the, no doubt,, considerable loss of gold during former crushing, there is, I think, some chance that, if economi-" cally worked, .and with approved gold saving appliances, ifc might leave a profit, notwithstanding the great expense con-, nected with the procuring of fuel (brown coal from Shag Point) for a steam engine.- ' '-. r - j # ,_ BEEFS OP SHAGTALLEY. i In visiting this locality Mr. Rich, of Bushy Park, and Mr, Harvey of Dunedin, kindly acted as my, guides and informants. The reef I saw has been worked on both sides of a steep gully; On the one side, the most extensively, _by Duncan, Glover, Reed, and Company, "on ' the other side by the Shag Valley Lease and Freehold Company. It consists of irregular larger and smaller bunches of quartz, ranging from less than an.inchJ.tp" several feet in thickness,. lying, between the beds of the country, a hard, grey phyllite, which strikes N. and shows an undulatingdiu; north-east-ward, at a nuan angle; of about 15°;. Work was suspended on account of the uncertain thickness and auriferous charr ,acter of the reef. A few;chains higher up the gully a similar reef, or rather a-suc-cession of interlaminated bunches; cot quartz, has been worked by adits: lane] opeir cuttings at several places on- the eastern hill-slope; but here also.work had to be given up for the same reason as iu the former case. Some of the quartz-; bunches paid very well, but ran quickly out, and it took all the profit made, aud more* : to prospect for other.'.. In" the neighborhood of this plan there are "the; ruins of a small battery of five heads of revolving stamps. I The Shamrock Reef.— This lies half a! mile north-eastward from the last mentioned workings, up the range, and consists of a bunch ot rather good-looking quartz, 2-3 feet thick at the surface, but running out at 4 feet in depth ; as proved : by a small shaft sunk on it. In strike it is traceable either side of the shaft for some distance, though apparently growing thinner. A trial crushing of two tons of the quartz is said to have paid loz. 18dwts. of gold. As this return must no doubt have left a good profit over working expenses, it seems strange that the reef has not been opened further. Maim, Beef of the Shag Vallty Lease and, Freehold Company. —This is the most important reef opened in the district. It lies not far from the Shamrock Reef, and has been worked by large open cutting, extending, with few interruptions, for 6-7 chains in length, along the slope of a steep range. It lies between the beds of the country, striking N. 40° W\, and dipping north-eastward intolhe range, at angles varying from 25-35 °. Its thickness ranges from 2 feet to (in places) over 4 feet, and it has the footwall pretty well defined throughout, but its hanging wall is broken and full of -small leaders. It consists mainly of quartz, which in large, solid bunches and veins lies mostly along the footwall, whilst towards the hanging wall there is a deal of mullock intermixed. The quartz is good-looking, seamy and slightly impregnated with pyrites. Regarding the yields from this reef, and the operations of the Company, Mr. Harvey gave me the following particulars:-After auriferous stone was discovered in the reef, and satisfactory prospects obtained by tin-dish trials from several places along the outcrop, as fat as the workings at present extend, 4 tons of the stone were sent to Ballarar, Victoria, and crushed-, at a good machine, with a result of-16|-dwts. of gold per; ton:,.. Another trial crushing of \\ tons, executed at the Government battery, Dunedin, gave 1 oz. 6 dwts. of gold. Encouraged by these satisfactory results, the Company erected crushing machinery, and gave the sufrply of 1,000 tons of stone from the reef in contract; but the first 500 tons paid at the rate of 4 dwtsj.tbe: second at'the rate of only 3 dwts.- of gold per ton; These low returns

did not, of course, by far, coyer the expenses, and the working of the mine was stopped in consequence. The crushing machine of the Company stands in the gully, near the firqt-men-tioned workings, about half .a. mile away from those last noted, aid-is very well constructed. It consists of two batteries, each of five heads of revolving stamps, supplied with self-feeding hoppers, and driven by a steam-engine, the necessary supply of water being obtained Jrbm' a good-sized reservoir, constructed a little higher up tbegully. In front of the batteries lie common amalgamated copperplate tables, and below these follow the blanket-strakes 14 feet in length, and with a fall of I.inch per foot. A .revolving barrel is provided for the treatment of the blanket-sand. ' ".''"..',

Whilst considering the Company to have acted very unwisely in erecting expensive machinery before the reef had properly been opened and prospected, to" say 50-80 feetj.in depth, la in of opinion, that it certainly deserves this trial, now that the machinery for testing the quartz is available. For, as regards the great discrepancy between the gold returns .'of the last, and those of the trial-crusliings, it seems likely in a'grcafc'measui*e to have arisen through the contract for the pm. vision of the 1,000 tons of quartz to the mill, inasmitch as the old workings plain ly show that far more mullock (from the hanging wall) '^as, than quartz. And from what Mr. : Harvey told me, it seems also doubtful whether these quarrylike openings are actually at these places which furnished the- stone for the trialcrushings. * . -r ~