MINING NEWS.

New Zealand Herald, Volume XLIX, Issue 14923, 22 February 1912, Page 5

MINING NEWS.

THE GRAND JUNCTION.

IMPORTANT DEVELOPMENTS.

AT THE SIXTH LEVEL.

Waihi, Wednesday. Tins morning in company with the manager (Mr. W. McConnachie) a Herald representative inspected the principal development points at the sixth level in the Waihi Grand Junction mine, and noted that the operations which have been conducted since his last visit have been attended with highly satisfactory results. The drive west on the Republic reef is now 19ft from the main south-east crosscut, with a full face of first-class ore '.n the drive. At a point 60ft in from the main crosscut the section of lode carrying the better value wont off into the south wall, and on being followed junctioned with the Empire proper, thus indicating that the Republic is the hangingwall portion of the Empire. A crosscut through the lodo at 100 ft west showed the width of milling ore to he 20ft. Going east the Republic has split into stringers, and driving has been temporarily suspended. Developments on the footwall lode and tho Empire proper going west make it quite clear that the former is an entirely new make of ore, quite independent of the Empire. This was proved by tho crosscut thrown out from the north wall of the footwall reef, 125 ft west of the main south-east crosscut, where between 30ft and 40ft of country rock, with two or three small bands of mineral ore were passed through before the footwall of the Empire was encountered. On the footwall lode the drive west is now out over 200 ft, and for the full distance driven and right across the drive all along the ore is high-grade, with rich sulphides in the present face. The full width of the reef is not exposed in the drive, but at 125 ft west a crosscut showed 10ft of sulphide ore. The average width will probably be about Bft, and the uniformly high values disclosed by sampling at regular intervals along the drivo show that the discovery is one of the moat important met with in the Junction mine. Preparations are now in hand for the sfoping of this block! and in No., 5 winze on the Empire from No. 5 level a crosscut is being thrown out from the footwall in search of the new make of ore.

On its eastern extension the Empire reef has been followed 180 ft, showing good grade quartz all the way, and a full face of first-class mineral ore in the drive. The face is already over 200 ft beyond the point at which the values gave out in the fifth level, thus indicating that the pay chutes continue to extend further east with depth. A rise put up has connected with No. 9 winze, and proves the existence of a good stoping block overbead, upwards of 100 ft in height. The south-east crosscut is now out 550 ft in a good class of country, and rather under 300 ft of driving should bring it into touch with the Royal reef, which will bo cut immediately under No. 19 winze, in which, at 80ft down from No. 5 level, a crosscut proved the lode to be 47ft wide, and worth between £3 and £4 per ton. The reef should be to hand about the end of March. North of the shaft the Martha reef is being driven upon both east and west, and the ore broken, though comparatively poor, is going to the mill. The west face shows a band of very fair grade mineral ore. about 2ft wide close to the hanging wall The north-west crosscut is now out 280 ft from the shaft, and at 240 ft. passed through a new make of quartz about 10ft wide, assaying about 10s per ton. The crosscut is travelling a favourable class of country, and should intersect the Mary reef in about 200 ft of driving. In the course of an interview with the general manager (Mr. F. W, Grace), ; after coming out of the mine, the visitor was given some interesting information concerning the comparative geological depths of the principal Waihi mines, and the occurrence and agency of manganese points on which there has recently been some discussion. The manager said: "The present bottom workings of the Waihi and the Waihi Grand Junction mines are practically at tha same depth below the sea level, but, geologically speaking, the ; Waihi Company a low level is upwards of 1100 ft below the outcrop, whereas the Grand Junction low level is but a little over 150 ft below the outcrop, as borne out by the occurrence oj pumico between the Empire and Royal reefs in the southeast crosscut at the fifth level. Further confirmation of this has been afforded as development has proceeded going east in the Junction, where it has indisputably been shown that the old surface of the ground still dips. These facts point to the strong probability of much longer extension of tho ore chutes, as depth is attained. With regard to the occurrence of manganese I may say that I do not consider it an unfavourable indication at all, because it is recognised on all goldfields containing manganiferoua ores that the leeching of the gold and silver values, and more particularly the gold values, has occurred in the upper levels or oxidised zones. This is no doubt due to the fact that the surface waters containing oxygen and sodium chloride ore are capable, in the presence of manganese, of dissolving the gold, but such waters in their downward percolation, fn coming into contact with the sulphide zone, will re-deposit such values, forming a zone of enrichment. I think that this zone has yet to bo reached on the Waihi field, at what depth, of course, at present no one can say. In one or two isolated places on the Empire foot wall lode (the new make of ore mentioned in your mine report), at tho junction of the sixth level there are patches of sulphide ore that certainly show signs of secondary enrichment, but I do not consider that the general zone of enrichment on this lode has yet been reached." •The general managor of the Waihi Grand Junction mine cabled the London offico of tho company as follows yosterday:—"Aro crushing 372 tons per day, the actual extraction is £1 163 3d. Main crosscut, north from main shaft, at No, 6 level, 286 ft- Martha lode No. 6 level, cast drive, 26ft, milling ore. Martha lode, No. 6 level, west drive : 38ft, value £1 12s 2d; hanging-wall exposed, but no footwall yet. Republic reef, i.e. reef 69ft south of shaft: No. 6 level, west drive 192 ft, 68in, value £3 7s, with no walls seen; this is probably main reof Empire lode. Empire lode, No. 6 level, west drive : Footwall leader 207 ft, 67in, value £14 4a 8d; footwall . exposed, but no hangingwall yet. Crosscut at 200 ft shows 108 in, value £3 18s 9d. No. 9 rise is now up 61ft, value £6 7s 6d. Footwall exposed, but no hangingwall yet; holed to winze. No. 6 level, south-east crosscut : 448 ft." TALISMAN. GOOD ASSAY VALUES. The superintendent of the Talisman mine, Karangaiiake, has despatched the following cable to the London office :—"Driving north from No. 6 winze, progress 35ft, reef 12in wide, values low. Driving north from bottom of No. 12 winze, progresa 13ft, reef 60in wide; assay value £20 2s 6d. Driving, south, progress lift, reef 45iu wide 5 assay value £19 7s 6d. Have commenced sinking Woodstock shaft. NOTES. In the Union Hauraki mine, Coromandel, the drive on the footwall branch of No. 2 reef has been advanced 25ft. The reef averages about 4i», and the quartz and country rock are of a good description being highly mineralised. The manager of the New Waitaia mine reports that in the north drive at No. 6 low level, a distance of 150 ft has been driven on the reef through a splendid

channel of country. During the week tho reef has turned over, and is now dipping east instead of west, as usual. It has also pinched to about 4in, but has improved in quality, nice streaks of good coloured gold showing consistently throughout tho ere. Some people would call it Eicked stone, but there is no doubt it is igh-grado crushing material. A soft, silica seam on what should be the footwall, but is now the hangingwall side, shows very coarse gold, some of it like wire, in the loose.

In the Otama, section of the Handsworth United mine, No. 3 stope is yielding very good general ore which prospects splendidly. About 41b of specimen stone was selected during the week from No. 3 and No. 4 stopes. The latter should also give good results, as in No. 3 stope gold has been left showing along the back for the last 30ft. A start has been made to pick up an old drive on the west side of the hill, with the main' object of improving ventilation. Until the "collapsed portion is opened up no idea.can be formed as to how far it is in, but from the appearance of the eld mullock tip the manager considers it will bo close to the present workings, where 40ft of sinking would connect the block, and in addition to giving good air in tho stopes would also permit tho extension of the main drive south. He regards this as a pvcry important work, as on the broken surface good prospects can be obtained in that direction.