a—9
30
Samples selected from the various exposures gave the following results on assay : .... Gold. Silver. Copper. .Molybdenum. "' Gr. IJwt.gr. Per Cent. Per Cent. 1. Northerly outcrop, Mount Scarlett ... -1 5 1 (I 27 006 2. Middle outcrop, Mount Scarlett ... o*s I 21 ... II (12 .'I. Southerly outcrop, Mount Scarlett II 15 o'o3 0015 On the ridge between Sluice and Tangent creeks, at an elevation of 2,930 ft.,* a 2ft. Vein •formation is exposed, highly mineralised in places with pyrite and ma reasite. A little zinc blende is also present. On the spur on (he north side of the gorge above Specimen Creek, anil again near the mouth of a small creek higher up the river, are exposures which are probably referable to one and (Insame vein .format ion. In the former outcrop the vein has much the appearance of a pegmatite dyke. It is from .'I in. to is in. in width, and apparently carries no mineral. The creek exposure is somewhat similar in character. It is about 6ft, wide, with large lenses of quartz, in places somewhat pyritised. Central Observations. All the veins as yet examined mi the northern side of the Little Wanganui Kiver have a uniformly north-easterly strike, with generally a steep south-easterly.dip. Ii is possible that the copper indications observed in the river-bed mark the southern extremity of a vein formation, of which the Sluice Creek and Mount Scarlett outcrops are widely separate,l exposures. The latter outcrop is, however, the only one so far met with on the northern side of (he river which offers economic possibilities. On the southern side of the river the most promising outcrops ale. as already stated, the Mount Radiant and New Anaconda reefs. It is probable that the outcrops in Piano Creek, and on the spurs to the north and smith of the Mount Radiant reef, are referable to this formation. It is possible that the New Anaconda reef may lie a further continuance al a lower level of the satue formation, which would in this ease have a strike-extension oi over iwo miles. Connecting OUtcrppS between the New Anaconda and Piano Creek outcrops have not so far been noted, bill jii.iv yet be found. . . Floaters of highly mineralised ore found in the bed of Copper Creek lead lo the opinion thai further examination of the slopes to the west of the waterfalls is warranted. Practically nothing has been done in the way of opening up known outcrops, or in endeavour ing lo prove their continuity along the line of strike. So steep and densely w led is the country that such work is extremely arduous, and could only be undertaken with the expenditure of con siderable capital. I'Ynin a consideration of the results of assays of the various samples selected from the two .main outcrops it will he seen that the ore iii general is very low-grade, the copper-* tents averaging less than I per cent. This percentage could, however, be readily brought Up to a Commercial standard by judicious hand-BOrting. It must be pointed out also that these results must only be considered as tentative, since the process of sampling was rendered extremely ditli cult and the results somewhat unsatisfactory, owing to the undeveloped state of the properties. It is proposed later on to undertake a more exhaustive sampling mi a larger scale, the results of which may ])rove more encouraging, and will be published in the final bulletin. The New Anaconda is undoubtedly; much the more promising of the two veins, owing to the comparative regularity of its values in the vein material and to ils continuity almio the Hn'e"of strike. In many ways it bears a striking resemblance to the veins of the great copperfield of Butte, Montana. Two of the samples, Nos. 2 and I, from this vein have a copper-content exceed ing 2-' i per cent., while the values in molybdenum, gold, and silver are not negligible. Owing to the specific gravities of chalcopyrite and molybdenite, the two principal minerals, differing bu( little, the separation of the two would appeal to be difficult. Their markedly different physical characters, however, combined with the fact that they are not generally closely associated in the ore, lead to the opinion that a mechanical separation should not prove insii itnount able. Analyses of samples Nos. 2 and I from the New Anaconda vein are as follows: — N". 2. Nn. 4. Silica (SiO,) ... ... ... ... ... ... 87-56 8608 Alumina (A1„0») ••• ... ... ••- •-• 110 084 Ferric oxide (Fe 2 O s ) ... ... ... ... ... 504 627 Lime (CaO) ... ... ... ... ... ... 010 010 Magnesia (MgO) ... ... ... 020 0 15 Alkalis (K„0, Na 2 0) ... ... ... ... ... 020 030 Cuprous sulphide (Cu a S)... ... ... ... ... 2*97 2-91 Molybdenite" (MoS„) ... ... ... ... ... 0-08 025 Ferric sulphide ... ... ... ... ... 275 315 10000 10000 Copper ... ... ... ... ... ... 2-37 232 Molybdenum ... ... ... . . ... ... 0-05 015 Total sulphur ... ... ... ... ... ... 1-90 214 (2.) Cold. So far no auriferous veins have been encountered by the Survey, but placer deposits of considerable richness, though of but limited extent, have been worked within the hounds of the subdivision. Such deposits'were found in branches of Or knife Creek in association with
* Barometric height.