Appendix 9.
Reefs and Companies of Skipper’s Creek.

Nugget and Cornish Company’s Mine.—This mine lies on the N.W. side of the Shotover River, and is managed by J. F. Rosk-ruge, who readily furnished me with all the required information. The Nugget and Reef strikes W. 43° N., and dips south-westerly at angles varying from 70° to 80°. It has well-defined walls, with clay casings, and crosses the country—a very fissile argillaceous mica schist—both in strike and dip. The present workings of the company, of which Mr. Roskruge prepared a detailed plan, are carried on from an adit, in an enormous slip, and are, on that account, of an intricate nature, and require great care in rendering them secure, as the reef varies there in thickness from 12 to over 20 feet in places. The adit is in a distance of 197 feet, of which the last 144 feet are on the line of the reef. The latter consists of quartziferous page 224mica-schist mullock, with veins and bunches of quartz, sometimes several feet thick. Both the mullock and the quartz are very abundantly impregnated with iron and arsenical pyrites, and contain gold, but the quartz is generally the richest. The average yield has hitherto been eleven to twelve dwts. of gold per ton. The reef is traceable for a very long distance. High up the steep mountain side, N.W., a strong leader was worked in its line by another party, and paid 4½ oz of gold per ton. Down the steep slope towards the Shotover River, below the slipped ground, it is plainly exposed, from 8 to 10 feet thick, and from there—some 180 feet perpendicular below the present workings—Mr Roskruge very wisely intends putting in an adit, which will give about 250 to 270 feet of Backs to rise upon. Beyond the river, up the opposite high and steep range, it has also been opened at several places and proved auriferous. There is another reef about 200 feet distant from the above described, higher up the mountain side, which strikes W. 35° N., and dips at an angle of about 50° towards it—the line of junction of both reefs in dip lying, according to Mr Roskruge’s calculation, perhaps close to the end of the working adit. This reef is from 10 to 12 feet thick, and has been worked down from the surface, also in the slipped ground, a depth of 100 feet, but there is still a good height of Backs available above the adit. The yields from it have in the average been about 16 dwt. of gold per ton. As regards the whole quantity of stuff crushed from the mine, it amounts to 6958 tons, which have realised 3624½ oz. of gold. The crushing machinery of the company, which stands close to the Shotover River, consists of three batteries, each of four heads of revolvstamps, of about 6 cwt. each, fed by hand, and driven by a turbine. As gold-saving appliances, are used amalgamated plate-boxes with three drop-ripples, similar in construction to those of the Elizabeth Company’s machine, Carrick Range, but improved by the addition of splash-boards for ripples. From these boxes, of which there are three—one for each battery—the stuff runs over only six blanket-strakes of 12 feet in length, and with a fall of 1½ inch per foot. The blanket-sand is treated in the revolving barrel, and the amalgam concentrated on a strake, covered with amalgamated copperplates. A similar, though longer strake, with a ripple at the end, serves for washing the stuff from the stamper-boxes. On account of the great amount of pyrites in the stone, much quicksilver is lost through becoming floured, and Mr Roskruge is also convinced of a considerable loss of fine gold. He intends soon to entirely rebuild the machinery, which is old and liable to frequent breaks, so much so, that only about 50 tons can be crushed per week, and he took notice of my recommendation to adopt the Clunes system of appliances. In reviewing my observations on this mine, I feel convinced that, if worked on the extensive scale which the size of the reefs and facilities of the ground permit, and with adequate good crush- page 225ing machinery, it would become one of the best paying ones in the Province.

Southberg’s Reef, Otago Company.—Managed by Mr Southberg. This reef, which is traceable for several miles in length, crosses the country both in strike and dip, striking E. and W. and dripping N. at angles varying from 35° to 60°. It has been opened from Skipper’s Creek both ways by adits, but the most extensive workings have been executed on the east side. The western adit is about 200 feet in length, and the reef, where broken into by a small cross-cut near the end, is 22 feet wide, representing in fact an enormous fissure, with well-defined walls and clay casings, filled with the country rock –a fissile, quartziferous mica schist, not very much altered or displaced, but richly impregnated with pyrites. Of veins and bunches of quartz, independent of the interlaminations of the latter, in which the country in this district is very rich, there are but a few observable, and the mass, as such, is altogether too poor to pay for working. On the east side of the creek the reef carried rich gold (1 to 9 oz. per ton) for a considerable distance along the surface, ranging in thickness from eight to sixteen feet; but on working downwards it was found to run poor at depths increasing towards the east, and the present low adit, though a considerable distance in, has not as yet struck it of a payable character. At some of the places opened it is from 12 to 14 feet thick. There are several drives branching off this adit, which have been wrought for the purpose of prospecting a strong spur, or dropper, which dips flat away from the reef, and has produced good gold in the upper workings higher up the range. As far as this spur has been opened by the drives it has not, however, proved payable as yet, though Mr. Southberg does not despair of finding it so on further exploration. It is in places from two to three feet thick, but thins gradually to a mere string as it approaches the reef. Considering the run of the good portion of the reef worked on this side, there can be no doubt that it represents a shoot dipping at a rather flat angle eastward in strike out of the company’s lease; and on this account, I fear, Mr. Southberg has no chance of finding payable ground—a new make—except in sinking from the present eastern adit. On the west side the prospects are, in my opinion, far more favourable; for the adit, if continued along the reef, has there a good chance of striking a new auriferous shoot, the existence of which is clearly indicated by good specimens and prospects having been obtained from the outcrop of the reef higher up the range. The present productive workings of the company are carried on in another claim high up the eastern range, in a large landslip enclosing the reef, similar as in the case of the Nugget and Cornish.

The crushing stuff from these workings contains abundance of vein quartz, and is very ferruginous, resulting from decomposed page 226pyrites, though the latter occurs also intact in pretty considerable quantity. The exact yield of the crushings was not given, but from what I could gather, it does not amount to much above 5 dwts. of gold per ton.

The crushing plant of the Otago Company consists of sixteen heads of revolving stamps, in four batteries, fed by hand, and driven by a turbine at a speed of about 60 blows per minute; weight of stamp, 6 cwt.; lift, only five to six inches; gauge of gratings, which are punched, 122 holes per square inch. The arrangements for gold-saving for each battery are as follows:—The stuff passes in succession a shallow mercury ripple, two and a half feet of copperplate, two blanket-strakes, four feet long; a rather narrow mercury ripple with a five-inch drop; and two blanket-strakes of six feet in length. Both the lower and upper strakes are two feet wide, and lie, in front of two batteries, at an inclination of one and a half inch per foot; in front of the other two, at one and a quarter inch per foot. The blanket-sand, which is very rich in pyrites, after being merely washed by tin-dish and in a strake, is left to decompose by exposure to the atmosphere, and is then passed again through one of the batteries, with gratings of 225 holes per square inch. Mr. Southberg knew that on account of the large quantity of pyrites much quicksilver was being floured and a great deal of fine gold lost, and he seemed inclined to adopt the Clunes system of appliances I recommended.

Phœnix (late Scandinavain) Company.—The ground of this Company, also on Southberg’s Reef, adjoins that of the Otago Company on the east, and, according to a plan, and sections prepared by Mr. F. Evans, the consulting engineer of the Company, has been extensively worked by and from several adits driven from the steep slope of the range. As these workings were inaccessible, I could not examine them; but from what I learned from Mr. Evans, the reef, which averages in them 8ft. in thickness, contains what appears like two large payable shoots (the yields varied from 6 to 25 dwts of gold per ton), dipping eastward in strike, and there is besides the chance of the rich shoot coming from the Otago Company’s ground, above-mentioned. The quartz, and this is the case in the latter company’s ground also, changes in character from crystalline and brown ferruginous in the higher to dense and bluish grey in the lower parts of the workings—in fact, the latter quality represents a so-called "new," or "second-make." On examination of specimens, I found it densely impregnated throughout (the cause of its dark color) with extremely fine particles of pyrites (iron pyrites with much arsenical and copper pyrites), and showing gold in very fine specks, It looks in texture more brecciated than seamy. The reef will in future be worked by and from a new deep adit, which, at the advice of Mr. Evans, has been driven from Skipper’s Creek, and struck the reef at a distance of 347 feet, page 227from which level there would be about 160 feet height of Backs available to rise upon. As regards the crushing machine of this company, erected about 8 years ago, and at present much out of repair through long disuse, it is the largest in the Province, and its system of gold-saving appliances resembles most closely that of the Port Philip Company, Clunes. It consists of 30 heads of revolving stamps in 6 batteries, each of 5 heads, supplied with self-feeding hoppers and driven by a powerful turbine in the centre. The coffers are of the Clunes pattern; weight of stamps over 6 cwt.; lift, 6-8 inches; gratings punched with 122 holes per sq. inch: at one time gratings of wire gauze were used, with only 81 holes per sq. inch. The stuff passes from each battery through three connected quicksilver troughs, with 8 inches drop, and supplied with splash-boards, and afterwards over blanket strakes of 14, 16, and 18 feet in length, for different batteries; some with 1, others with 1½ inch fall per foot. The quicksilver troughs are rather narrow, and concave at the bottom, which is not as good as if they were flat, as the quicksilver is more liable to be splashed over in front. The stuff from the stamper-boxes is washed in a large tie. For the treatment of the blanket sand, which is very rich in pyrites, serve a large revolving barrel with a broad shaking table and rippled ties attached; and after passing these appliances, it is put aside to be ultimately ground with quicksilver in a large arrastra, for the purpose of extracting the gold from the pyrites. The yield of the sand by this latter process has varied from 3 to 12 oz. of gold per ton; loss of quicksilver not ascertained. There is also a reverberatory furnace, built after the old Cornish model, within the mill house; but this has not been in action for the last six years, on account of the fumes being unbearable and dangerous to the men working in the building. According to what Mr. Evans told me, he understands the process of the extraction of the gold from the pyrites well, and intends to build and work another furnace after the Victorian model, outside the mill. Besides this, he purposes erecting in front of the batteries several Borlase’s buddies to ensure a more satisfactory saving of the pyrites. With these contemplated improvements executed—considering the capabilities of the mine, as stated by Mr. Evans—it ought to rank soon amongst the dividend-paying ones of the Province, more especially if the occasional short supply of water for the crushing works is obviated by the construction of the proposed new race. There have been a number of other claims and reefs worked in the district, of which Mr. Evans kindly gave me the following particular:

British American Claim.—It lies on Southberg’s Reef, 600 feet east, up the range. The reef, being there 3 to 4 feet thick, was opened by a shaft and the stuff obtained paid 11½ dwts. of gold per ton. The party then drove to an adit to strike the reef about the site of the shaft; but having had no survey for guidance, page 228went nearly 300 feet out of the line, and never reached the reef. There has been nothing done since in the claim. Between 300 to 400 tons of stone were crashed by the machine of the Nugget and Cornish Co., which once belonged to the party.

Prince of Wales’ Reef—Is a continuation of Southberg’s Reef, westward, high up the range. It was from 15 to 20 feet thick where opened, and paid from 7 dwts. up to 1 oz. of gold per ton; but the stone crushed was mostly picked.

Pactolus Reef—It lies north of the Prince of Wales’ Reef, is about 6 feet thick, and has a north and south strike. The prospectors opened it for 20 feet in length, and had a trial crushing which yielded at the rate of 6 dwts. of gold per ton. As this did not pay for working, it was abandoned, and has not been further tried.

Sawyer’s Gully Reef.—It was 3 to 4 feet thick on the surface, but pinched in depth. Three tons were crushed, which yielded 4 ounces 12 dwts. of gold. There has been nothing done on it since.

Butcher’s Gully Reef.—This was 20 feet wide where opened, and a trial crushing paid 7 dwts. of gold per ton. After this it was not further tried. The gold it carries is very fine.

Ophir Reef.—This lies about half a mile from the Nugget and Cornish Reef, up the Shotover River. It is plainly exposed in a landslip, and carries fair gold. The prospectors spent £600 to £700 in trying to find it in undisturbed ground, but without success. The mode and manner of conducting the search, has not, however, been the most judicious, according to most opinions.

Hercules Reef.—This is a continuation of the Nugget and Cornish Reef. Where opened, it was 5 to 6 feet thick, and a trial crushing paid 5 to 6 dwts. of gold per ton. Although better stone was known to exist, it was given up, and has not received any further trial.

Southland Reef.—This lies about one mile south of the Hercules Reef, nearly 600 feet above the Shotover River. It is a mullock Reef with bunches of quartz, which are more or less rich in gold. A yield of 45 ozs. was obtained from 14 tons crushed. One of the prospectors was killed during working, when afterwards a shaft, sunk on it to a depth of 50 feet, struck much water, it was deserted, and nothing has been done on it since.