The Critic, Adelaide 28 October and 4 November 1899 - Ruddygore Group — This consists of the following four 30 acre leases: Lease 28M known as Ruddygore No. 3.5. Lease 27 known as Ruddygore No. 2.5. Lease 26 known as Ruddygore No. 1.5. Lease 25 (31 acres 2 rods) known as the Ruddygore. It is outside the limits of the limestone belt, and the formation (regarding the outcrops in lease 28 also as portion of the same dyke) appears to be distinct from those inside. Its structure is entirely dissimilar from them; and also, indeed, from any other of the companies properties which have so far come under my notice. The mine is situated quite outside the limestone belt, and represents a dyke in granite country. The rock composing the dyke is porphyry, and it has a surface outcrop of perhaps 12 acres. Its main mass on the surface constitutes a low, rounded hill of approximately the same altitude as the adjacent granite hills.
The principal portion of the deposit is roughly lenticular in shape, and is mainly situated within the boundaries of leases 25 and 26. Its length is about 20 chains (402m), while its width is up to 6 chains (121m), with an average of perhaps three or four (60-80m). Its strike, or direction, of its longest axis is north-west. Outcropping on various parts of its surface, or back, may be seen in places amongst the grass small areas of granite, although whether these occur as bosses or dykes I am unable at present to determine. If as dykes then the deposit maybe regarded as a series of parallel porphyry dykes divided by intervening bands of granite. However, assuming it to be a single dyke it may be said that its mass has been much dislocated and disturbed, as is clearly shown by the faults that may be observed in the sides of the different excavations. Throughout the dyke mass there occurs a thoroughly irregular system of very numerous and small veins, strings, and nests of quartz, occurring everywhere and anyhow, running in each and every direction, and interlacing with each other promiscuously. These occur more plentifully in some places than others; also some are larger than others, but the average width of the veins appears to be about 1 inch (2.54cm); and they are made up of aggregations of beautiful hexagonal crystals of quartz, showing pyramidal terminations. The crystals are usually from one-quarter to 1 inch in length and generally show perfect crystallization.
Ruddygore ores are mainly cuprite (copper(I) oxide Cu2O), melaconite (melaconite is a mineral consisting of cupric oxide, CuO, and known also as black copper ore is an earthy black oxide of copper, arising from the decomposition of other ores), and azurite (copper carbonate mineral, deep-blue copper mineral produced by weathering of copper ore deposits - secondary mineral), while below are found (1) the sulphides of copper, chalcopyrite, and bornite; (2) the sulphide of lead, galena; (3) also some iron and arsenical pyrites.
As regards the work done the accompanying section may be referred to: Z is the footwall rock, granite; Y is a zone 15 or 20 ft. wide of ore, impregnated granite, richest nearest the porphyry; B is the footwall of the dyke, and is very undefined; C is a shaft 100 ft. deep, known as No. 1. It is wet, and requires constant baling. The haulage gear consists of a whip only. The first 70 ft. of the sinking was through porphyry; then the shaft passed through the underlay, and gradually entered granite, in which rock it continued until sinking was stopped. At the 90 ft. level a crosscut D has been driven a direction of 70 deg. east of north and is now in a total distance of 91 ft. For about the first 20 ft. this crosscut was in ore, impregnated granite; then the porphyry proper came in — although it is impossible to tell clearly where the one rock ends and the other begins owing to the same agencies having similarly affected both, the result being a gradual merging of one rock into the other, the zone of contact alteration having a width of perhaps 20ft. For the next 35ft. or so the crosscut has intersected a zone of porphyry containing perhaps 5 per cent copper ore in sulphide form. The ore includes just a little galena, and the general appearance of the crosscut is very fine. This crosscut proves the ground between it and the bottom of the open cut. At this depth the ore occurs in strings, threads, bunches, and veins, which may be regarded as portion of a thoroughly irregular network of quartz seams interlacing the porphyry in all directions. For the balance of the distance the crosscut seems to have passed through a harder porphyryic material containing the usual seams and some ore, but on the whole is not nearly so rich as the preceding 35 ft. Possibly this harder and much altered, for from the patches of granite boulders showing in various places on the hill surface it may be inferred that the porphyry dyke is traversed by granite here and there, and a crosscut at 100 ft. right across its strike should determine in what form the granite occurs, whether as dykes, bosses, or otherwise.
The management intends to continue the crosscut D under shaft F (No. 1) and connect for air, the temperature of the crosscut at present being abnormally high for the depth of the ground. E is an open cut 178 x 66 x 46 ft. — width and depth taken where my section crosses it. A small hill, or more properly speaking, a strong outcropping mass, carrying rich ore, originally occupied the site of this cut. But the outcrop has been removed, and a cut of the above dimensions has been excavated. The management estimates that the ore taken from this cut amounts to 8,000 tons of 5 per cent copper, besides smaller heaps of much richer ore. The ore is stacked at the end of the inclined tramline running into the cut, and presents a very fine sight. The crosscut D has proved the ore going down underfoot in the open cut. At the depth of the crosscut its quality and character are maintained. F is a new shaft known as No.2. It is now down 50ft. in an altered granite (?), representing probably a dyke traversing the porphyry. In its bottom of occasional irregular seams of iron pyrites are now being obtained, so that it is probable the shaft is nearing the underlay of the richer porphyry. H represents a dry gully, and I old workings showing copper ores. At this point there are a few small heaps of mineralised stuff that look like decomposing arsenical pyrites. A is the hanging-wall of the deposit, and M the country rock. A considerable number of surface trenches have been put in over the general surface area of the deposit, and all show the same general characteristics and satisfactory prospects. On lease 28 also there are isolated outcrops of formation, which have been trenched with the usual results. The Ruddygore smeltings on lease 25 have been: 93tons at 2 oz. silver and 6% copper per ton. and 844tons @19.28% copper. Just as it must be admitted that the open cut and the crosscut have only developed ground directly underneath the part of the deposit where the surface indications were the best, so also it must be borne in mind that in comparison with the general body of the porphyry mass the ground proved by such worth is insignificant in extent. The surface indications showing over the other and by far the greater portion are not to be compared with those which originally showed over the open cut. The work so far having been confined to where the surface indications were strongest it follows that nothing has been done to test how the general body is likely to develop below where the surface indications are weaker, so that everything with respect to the probable development of the general and therefore more important body of the deposit is left to inference. Still, it seems a fair thing to expect that while not much of the ore body may prove to be directly smeltable yet a great part of its bulk should furnish a vast quantity of poorer stuff suitable for concentration, and the general features of the deposit appear to be such that there will be well founded reasons for disappointment if, when it is systematically worked, it fails to develop into a heavy and consistent producer.
Barrier Miner Broken Hill 10 Jan 1900 - The Ruddygore hill, covering three 40 acre blocks, has been penetrated 45ft beyond Moffatt's cutting. The tunnelling is continuing in profitable ore, the bulk value so far being 5% copper, 3oz silver and 2dwt (3.1g/t) gold.
The North Queensland Register, Townsville, 22 Jan 1900 - Those who have visited Chillagoe have always regarded the Ruddygore mine as being the property included in the properties owned by the Chillagoe Railways and Mines Company. It is rather a low grade proposition, and the probabilities are the the ore will be concentrated before it is smelted. The Ruddygore hill covers three 40 acre blocks and is presumed to be a stockwork formation throughout. It has been penetrated 45ft beyond the extreme end of Moffatt's cutting. The tunnel is continuing in profitable ore, the bulk value so far being 5% copper, 3oz silver and 2dwt (3.1g/t) gold.
The North Queensland Register, Townsville, 23 September 1901 - The Ruddygore Mine - The most recent development work undertaken at this mine is proving satisfactory. A paddock of about 40ft square has been put down, and is being carried in the direction of the tunnel, showing ore all over the area excavated, with numerous rich veins throughout the whole formation. In the tunnel end of the cut the face is 6ft high, and between that point and the mouth of the tunnel, a distance of 60ft, is ore, apparently of a similar quality. The ore is being picked, the richest assaying about 25% copper and the seconds 6% copper, and of the latter there is a heap of probably 300 tons stacked. In the eastern face of the open cut the copper pyrites is rich and plentiful, and the bounds of the deposit have not been reached at any point, and for a considerable distance in, the sides and roof of the tunnel shows patches of rich sulphides. The ore is being hauled up a steep tramline by two horses for the present, but the erection of a winding engine is contemplated, which will greatly facilitate operations and permit of a greater number of men being profitably employed. From present appearances this mine should be able to supply the furnaces with a very large quantity of payable ore. A winze sunk by John Moffatt and Company at the entrance of the open cuts being pumped out and Mr Danvers Power will shortly inspect it, its depth is about 35ft.
Year
Tons
Copper %
Silver oz/t
t x % Cu
t x oz Ag
1
1899
93
6
2
558
186
2
844
19.28
16272.32
0
3
8000
5
40000
0
4
1901
300
6
1800
0
5
1903
394
5
1.4
1970
551.6
6
1904
4225
5.3
2
22392.5
8450
7
1905
8
1906
5277
4.2
2.1
22163.4
11081.7
9
1907
4753
4.8
3.3
22814.4
15684.9
10
1908
4139
3.6
2.5
14900.4
10347.5
11
1909
10505
2.9
1.1
30464.5
11555.5
12
Total
38530
4.50
1.50
173335.5
57857.2
Approximately 1729t copper and 58,000oz silver from records I have found so far. More records to review so more posts to come and hopefully some more analysis than presented here.
BMR Price at posting:
18.3¢ Sentiment: Buy Disclosure: Held
(20min delay)