REPORT ON GOLDFIELDS OF OTAGO.

Mount Ida Chronicle, Volume VI, Issue 324, 21 May 1875, Page 3

REPORT ON GOLDFIELDS OF OTAGO.

BY Q. H. H«. ? l7jJttl.QHi ESQ., P.G.S,

„ BEEFS O.F,THE. BOUGH BIDGE., . ~.,„ ' \dontinued from pur last.] '"'" In visiting this district we were accompanied by Mr. James "Hazlett, M.P.C., who kindly afforded me some information about the drift workings of Tinkers and Drybread passed on the road. At the Bough Ridge we found only one enterE rising man, Mr. Withers, employing laor in re-opening a reef, once worked by the old Ida Valley Company, though over twenty other auriferous reefs are said to have, at one time been worked in the district. The reef Mr. Withers is engaged re-opening, and about the history of which, and many> others—the principal ones formerly worked—he kindly afforded me the subsequently given particulars, is the Homeward Bound Reef. The old main openings, from which exploitation has beeri'carried on, consist of an adit 770 feet in length, driven from a, gully in the strike of the reef; and of a shaft sunk from the hill slope a depth of 110 feet, passing the adit at about 50 feet from the surface. The reef is not a solid and defined one, but consists of a series of quartz leaders, of varying length and thickness, running close together an a defined line of strike, viz., 30 6 S., and dipping steeply towards ; each other. , Some join also m .strike, and, whilst ono ceases, another generally [commences sideways, or a. few feet fur-

ther on. This band of leaders, which is traceable for a considerable distance S.E. tip'the ranges traverses a fine blue phyllite, which dips slightly westward, and looks much disturbed by joints and faults, which also affects the leaders, . A fault of several feet in the strongest of the" latter .is, for instance, observable in the vertical shaft, where this passes the adit. It is not at all unlikely that the country,.becomes more settled,, and some of the main leaders join and form a defined reef in depth. -This seems to be indicated by a body of .'fine looking quartz—four feet thick, andcarrying payable gold—having been struck and left at the bottom of the shaft. Mr; Withers, who is at present engaged in taking out some payable stone from what appears to be. the main leader, left by the old company underfoot of the adit, intends soon to try his chance—and it is, I think, a very, good one —ia depth by sinking amain shaft near the mouth of the adit. For, irrespective of finding there a strong defined reef, from what he observed about the run of the gold, it seems to dip in shoots north-westward, i.e., from the hill towards the gully where the adit commences. The quartz.of the leader worked, which is but slightly mixed with mullock, shows a fine seamy structure, and is abundantly impregnated with iron and arsenical pyrites, whilst the richer gold-bearing stone is characterised by additional impregnated particles of zincblende and bournouite. ' The old Ida Valley Company had a fine crushing machine —the one bought by the Alta Company, JBendigo, noticed at another place—but they worked it very badly, and' lost, besides gold, a large quantity of quicksilver, some say nearly a ton weight, in a short time. Mr. Withers' crushing machine consists of a battery of five heads of revolving stamps of 5f cwfcs. each, fed. by hand, and driven'by a small steam engine. He uses gratings 122 and 144 holes per sqaare inch, but generally'the former. The crushed material on leaving the battery passes first through three shallow quicksilver 'ripplesj then over a common copperplate table, and untimately over three blanket strakes, about sixteen feet long, and laid at an inclination of one and a half inches per foot. For the treatment of the blanket said are used a revolving barrel and a'shaking' table; As Mr. Withers knows from experiments that the pyrites, which form a large percentage of the sand, are richly auriferous, he preserves the latter'for future re-treatment. The Clunes system of appliances, which I described to him seemed much to please him, and he may likely give it a trial. Lloyd's Reef. —This runs at a distance of about 100 feet S. westward from, and parallel to, the Homewardbound Reef. Besides having been worked l —also by the old Ida Valley Company —by small shafts here and there along the surface; it was opened by a crosscut from near the southern end of the 1 adit on the above reef, and proved, where struck to be about six feet thick. On driving on it, r a fault was foundto • cut it off close to "this'point W: westward in strike, and the 4. faulted portion was not recoj?ered:; i sputh.-eastwardifc : continued, however, wcilrdefinecf, though gradually thinning to ab6ut one foot, and was follpw-ed a distance of about 300 feet, and stoped out from the level to very near'*! the surface —the quartz paying > very-sa- ■ tisfactorily:- Mr.- Withers" intends prospecting for this reef—-the above-noted faulted portion—by ;a.cross-cut from.his. contemplated new main shaft, and is not at all,unlikely to discover it, judging from indications of the; reef on the' surface j abreast of the adit.- ■ v"

Great Eastern lieef.—This lie's about £ mile north abreast of the Homeward Reef, and strikes S'.E. with a-dip NUfAafc-'an angle of .85 °., traversing very flatrbedded phyllife, and showing well defined walls. Jit has been worked for. several hundred feet in length, and4o : t6 60 feet in depth, partly, by open cutting,'~partly by. and From an adit'abbut:2o0 r feet long:, : aLt the mouth of the'adit ; a shaft was sunlr : bn- ; it a depth of 70 feet, "when a strong pressure of water prevented 'further sinking withy out pumping machinery. lAit 'the of this shaft the reef is said tb'be left 18 inches thick, and.carrying better gold than found in the main workings. In these, its thickness ranged from a few inches to three feet—average/ about If ft.—arid it consisted of quartz and mullock; : the (ormer much The gold occurred in shoots, dipping Ni westward in strike,. similar as in the Homewardbound Reef. There have been several 100 tons of stone crushed with an average yield of about 1 oz. of gold per tori—the yields having ranged from -7 dwts; to ,2 oz., and, from some narrow parts of. the reef; even to 3 oz. of gold per ton. About three chains N.W. from the mouth of the adit, on a low rise, bounding the gully which runs up to the above workings, some open workings have been carried, on,; and small shafts sunk on what appeals to be ; the continuation of this reef, and from th.ese. also some good gqldis said, [to, have .been Qbtained. ' The cause of the desertion of the .reef l?y'the Great", IDa'stern party, who work~ed itJ&rst, and by the Energetic, CJpmpany, who worked it subsequently;"iS'"said' to lave been partly bad management, v partly want of enterprise in erecting the necessary jumpihg machinery for opening it in. depth-y-a trial lurbJcK' it, in my opinion, certainly deserves. ■■'■•'■•• .'•■•'.'-"■ ■••- ■ -'•■-

• West of JSngland Beef. —This was formerly worked by tHe Sons of Temperance. Company by an adit, open cuttings and shafts about eight chains northwards from the mouth of. adit> on the Homewardbound Reef. J ]> strikes -E 15° S, and dips northward at an angle of 56 °. Its thickness; ranged in the old workings from 6 inches to 18 inches, and it pinched and expanded it very short distances. The gold occurred in a shoot that dipped west- 1 ward in striked A considerable quantity of stone was crushed which yielded from i 5 dwts. to 1\ ounces of gold per ton. The reef has .been traced by .shafts .several chains westward under the alluvial of a flat: adjoining the workings ; and, as the gold struck was found to dip in that direction, it might not turn out a bad speculation to properly prospect it there, though !on account of the water,; no doubt to be met with, a-horse-whim would likely be required, in.rsinking below ..a: shallow 3epth. .;: .. ; .:..: . . . Surprise Reef.—This is a small reef, only about one foot thick, and has not been much opened/ 63 to 80 tons of stone crashed yielded from 14 dwts. to'lj oz. of gold per ton—a return which'did not payj as the expenses were too high at the time. Queen of the Isles Reef. —It lies between the Great Eastern and Homewardhound Reef, near the line of former, and was worked several years ago by the Ida Valley Company to the depth of about 40 feet. Its thickness ranged from about 1 to 2£ feet, and about 100 tons ortiahed

from it paid from 10 dwts. to 17 dwts. of gold per ion. There lias been nothing done on it since the company broke up. New Reef. —This has .lately been discovered by Mr. Withers, who is sinking a shaft on it. Its position is about f mile from the Homewardbound Reef. Whilst dipping nearby vertical it runs N;E., a course crossing the line of' all the other reefs. It consists of coarsely crystalline quartz, is about 7 inches thick, and has one good wall. A crushing of 28 tons gave the handsome return of \\ ozs of gold per ton. This reef crops out within a zone of country perhaps over a mile in width, which is full of a number of small reefs and spurs, 40ft. and less apart, running more or less parallel, of which many have been opened and proved auriferous. Before leaving this district, T may mention what Mr. H. J. Cope informed me of, namely, that at Sutton, Strathtaieri, a large reef has some time ago been worked by M'lvor, and Co., called the Ricassoli Reef. This was about 7f feet thick,, and consisted of 6ft. of white quartz, with 18 inches of mullock running alongside. The first crushing paid 2oz. 9dwt., the second loz. 13dwt., and a third of twenty ton,3, 13dwts. of gold per ton, which latter, did not cover expenses. The crushing machine used- consisted of an atmospheric two stamp battery, driven by steam. The mullock vein, which was the gold-bearing portion, ran out in depth; of the white quartz, vnone. was tried. Prom the fact that the gold, after retorting, turned out black, it is, no doubt with truth, surmised that some bad metal was in the stone, which caused a loss of gold during crushing.