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Eine Informationsreihe des Böcksteiner Montanforschungszentrums Radhausberg |
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.............................................................The position at the mine seems very clear. The property covers a large area, and of course I did not see everything. That would take months.
Present interest is confined to two areas or sections, the Radhausberg and the Kolmkar massives. In both these areas there are numerous and extensive old workings, mostly high up and in the vicinity of the contact between the intrusive gneiss and the overlying sedimentaries. These latter have been largely removed by erosion, but, nevertheless, the old workings seem to be entirely confined to the marginal, or contact zone of the gneiss. The whole district is dissected by deep valleys with steep and precipitous sides, but, despite this, the ancients apparently never worked anything low down. They stuck to the top, high up, in the contact area, which is what one would expect. As far as I could see and learn they never had anything large, only small narrow ore-shoots, but, doubtless, richer than in depth.
It must be considered also that they could work such deposits much cheaper than is possible today and were satisfied with a return which would be useless to modern workers.
The present company first confined its attention to the Rathausberg, where the ore-bodies are rather larger than elsewhere, until the veins were cut off, or died out at a fault, work was abandoned in that section and a scheme elaborated to work the Kolmkar, or Geissler section, which had been idle for 200 years. An ambitious scheme of low-level tunneling was commenced and some 6 to 7 kilometers of driving was done. In the course of this, one of the old ore-shoots in the Geissler was undercut, in the contact zone, and about 30.000 tons of ore taken from below the old workings, and milled in a small experimental plant of 20 tons daily capacity. Much driving was done upon a series of veins, or faults, which were cut at depth, and a small amount of ore, approximately 7000 tons was blocked out, and partly stoped and milled , leaving about 5-6000 tons standing there yet.
The drivage at depth has shown that the ore-bodies are very small, narrow scattered lenses, extremely erratic both in occurrence and in extent.
Still over the whole extent of the new workings upon the various veins, there is probably a fair tonnage awaiting development, but practically nothing blocked out. The work has been almost entirely confined to one horizon only, without raising and intermediate drifting. Consequently there are practically no reserves in the shape of ore developed by exposure on three or more sides. With one exposure only, ore found thereby can only be classified as "probable".
It is impossible to measure, or estimate, the total tonnage overhead, from a simple exposure in the roof of one level.
The ores consist mainly of narrow and small bunches of mixed sulphides of a fair grade in themselves alone, but cannot be mined without the admixture of much low-grade vein matter, which results in a milling-grade of about ten grams gold per ton; of which about 65%, roughly, has been recovered in the mill. Taking also into account the.....
see all the text (implemented February 8, 2009). |
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Mister BROMLY‘s private letter (1930) Abstract: An English Mininig Company decided 1930 to send an expert who should find out the prospects of restarting work at the socalled Siglitz-Bockhart-Erzwies-Area. Shortly after having seen the property, he wrote to a friend about what he had seen during his visit at Böckstein and about his discouraging impressions. |
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