Lode (mining)

“ Much ignorance is displayed on the subject of lode formation and the deposition of metals therein, even by mining men of long experience. Many still insist that lodes, particularly those containing gold, are of igneous origin, and point to the black and brown ferro-manganic outcrops in confirmation. It must be admitted that often the upper portions of a lode present a strong appearance of fire agency, but exactly the same appearance can be caused by oxidation of iron and manganese in water. ”

“ The principal minerals, in order of value of output, are gold, copper, coal, lead and silver. Between 1858—the year of the placer discoveries on the Fraser river and in the Cariboo district—and 1882, the placer yields were much heavier than in subsequent years, running from one to nearly four million dollars annually, but there was no quartz mining. Since 1899 placer mining has increased considerably, although the greater part of the return has been from lode mining. ”

“ Large areas, although so popular in England, do not compensate for large bodies of payable ore; the most remunerative mine is generally one of comparatively small area, but containing a large lode formation of payable, but often low grade, ore.
It is worse still, of course, to buy a practically worked out mine, though this too is sometimes done. It must be remembered that mining, though often so profitable, is nevertheless a destructive industry, thus differing from agriculture, which is productive, and manufactures, which are constructive. ”

“ Double Faulted Lode.
The success of a quartz mine depends as much on favourable working conditions as on its richness in gold. Thus it may be that a mine carrying 5 or 6 oz. of gold to the ton but badly circumstanced as to distance, mountainous roads, lack of wood and water, in some cases a plethora of the latter, or irregularly [73] faulted country (Fig. 17) , may be less profitable than another showing only 5 or 6 dwt., but favourably situated. ”

“ A zone of sheeted rocks like schist or slate, if sufficiently mineralized to warrant mining, would be a lode. Sometimes, in certain districts, the earth's crust has been subjected to many approximately parallel, closely-spaced fractures, and by the subsequent filling of these cracks, with the accompanying corrosion of the walls and their replacement by ore, extraction of the entire mass of rocks across a considerable distance will be found to yield a profit. Any such body is a lode. ”

“ On payable gold being found and reported to the Warden, the prospectors are entitled to a reward claim which varies from two to twenty claims of the ordinary area. 50 feet frontage are allowed to each miner on river and creek claims. On ordinary quartz claims, 50 feet along the line of reef, by a width of 400 feet, are allowed. The extent of ground in any lode claim not to exceed 3 chains by 5 chains, alluvial claim not to exceed 4 chains by 4 chains. This area may be increased by the Warden when the ground is poor, or expensive machinery has been erected. ”

“ Lying between the mountain ranges and running in the same direction are valleys containing arable land, while on the benches and lower hills are excellent grazing lands, on which grow nutritious bunch-grass and other valuable native grasses. In all parts of the State mining is being profitably pursued, and almost weekly new and valuable discoveries of the precious metals are somewhere being made. ”

“ Upon the bed-rock is a deposit, from three to four feet in depth, of gravel and boulders, in which the gold is hidden. This is called by the miners "pay-dirt," and to remove it to the surface and wash it is the end of mining. It is an expensive and laborious process indeed. The water has first to be controlled; and in mines of not too great depth this is done by a drain ditch along the bed-rock, commenced many claims below. In this all the claim-holders are interested, and all contribute their quota of the labor and expense of digging it. ”

“ The miner and the investor have generally confined their attention to iron, copper, and lead—metals that occur in huge deposits—and have disregarded the less assertive tin and gold-bearing alluvials which, when scientifically developed and economically managed, will give larger returns than any other mining in the world. ”

“ That ton would have to be ’packed,’ as they say here, eighty miles over the roughest of trails to Cody, and there loaded on cars and sent clear to Omaha, our nearest smelter. And I guess you know more than I do about the costly process of crushing ore and extracting gold from it in a smelter. It’s not like mining for ’pay dirt,’ as the men here call 137 placer mining, where you gather up sand and wash it out yourself and find the particles of gold in the bottom of your pan. This quartz digging is the most expensive kind of mining there is. ”

“ The modus operandi of single-handed mining may be described in a few words. The earth is loosened with the pick, thrown into the wheelbarrow with the spade, rolled to the river, emptied into the cradle,{150} washed by pouring water over it from the bucket, and carefully rocked until the gold is separated from the dirt. The clods of earth, during this process of washing, slowly dissolve, or are suspended in the water, whereupon the gold, (if there is any,) being heaviest, sinks to the bottom. ”

“ In a cablegram recently received from the Company’s administrator on his return from a tour of inspection of the various mining districts he states that new finds were occurring everywhere daily, and that crushings were everywhere successful; that the reefs were improving with depth, and that wonderful development was proceeding in every district. As regards alluvial gold, that large deposits do exist, and that their discovery is only a question of time, is the opinion of all experienced miners. ”

“ The ore as taken from the mine concentrates four tons into one, which has a gross value of one hundred dollars, and with the first concentrator, whose capacity was one hundred and twenty tons daily, returned three thousand dollars per day to the owners. The company employ one hundred and fifty men, and are well equipped for profitable mining. ”

“ These deposits are naturally the first to fail in productiveness, but the neighboring hills are formed of a gold-bearing quartz which is being crushed, night and day, by hundreds of powerful machines; and the works still pay ten thousand miners fair day-wages, besides giving the organized companies who employ them satisfactory dividends. Thus mining has been largely robbed of its adventurous character in this neighborhood, and perhaps also of most of its alluring charm, having become a sort of regular industry, like coal-mining, or even brick-making. ”

“ The ore is free gold in- decomposed quartz, and resembles the product of the White Bull mine, assaying, in some instances, twenty-six thousand dollars to the ton. At present this mine promises to hold out for a year or more of milling, in which case the company will secure an ample fortune for all.
Why these mines are not more developed may be owing to several causes. Primarily, a heavy expense attends quartz- mining anywhere, and in a country so difficult of access it is increased. ”

“ The holder of a miner’s right is entitled to enter upon any Crown land for the purpose of prospecting and searching for gold, and to take and maintain possession of a parcel or parcels of land and work the same, subject to the regulations and provisions of the Act; he is also authorised to cut timber for removal or for the erection of a place of residence or of business, and with the Warden’s consent, to make tramways or roads for mining purposes. Claims are of four kinds—alluvial deposits and river or creek beds; quartz lodes, reefs, and leaders ”

“ I could go on for hours, Jim, telling you about the Australian gold-fields, but I've said enough to show you that I meant what I said when I suggested that it was a pity that you hadn't found gold. The mining of every other metal needs a lot of capital to begin with—as gold does, when you begin to work a reef—but, in nearly every gold deposit, there are placers or pockets where a man can clean up quickly. ”

“ About two-thirds of our gold is obtained from the placers, and one-third from the quartz.
A mine is defined and generally understood to mean "a subterraneous work or excavation for obtaining metals, metallic ores or mineral substances;" but this definition does not apply to our placer mines, which are places where gold is taken from diluvial or alluvial deposits. Most of the work is not subterraneous; it is done in the full light of day. ”

“ Of course in large alluvial claims, where capital is employed, such appliances are superseded by steam puddlers, buddles, and other machinery, and sometimes mercury is used to amalgamate the gold when very fine. Hydraulicing is the cheapest form of alluvial mining, but can only be profitably carried out where extensive drifts, which can be worked as quarry faces, and unlimited water exist in the same neighbourhood. When such conditions obtain a few grains of gold to the yard or ton will pay handsomely. ”

“ Wooden booths flung signs to the streets bigger than the booths themselves: "Mineral Companies Promoted," "Mining and Smelting," "Mines, Options, Leases,"—there was no end to the variations of the eternal theme of mining. Town lots, switches of flats, and hill ridges were being swapped and sold and leased from the curb-stone; leases were being made from buggies and options were being granted from a horse's back. ”

“ Mine à La Motte has also proved an extensive deposit, and is still unexhausted. New Diggings, Shibboleth, and Richwoods, are among the discoveries of later date, which have yielded very large quantities of ore. But the mode of mining in the diluvial soil must exhaust it of its mineral contents, and direct miners, in after years, to the true position of the ore, in the calcareous rock. So long as the search continues in the soil, the business will partake of the uncertainty which now attends it, and which renders it rather an object of temporary enterprise, than a fixed employment. ”

“ A “face” is formed in the drift, and the water played against the lower portion of the ledge, which is quickly undermined, falls, and is soon washed away in the stream of water, which is conducted through sluices with riffles, and sometimes over considerable lengths of amalgamated copper plates. This class of mining has been most extensively carried out in California and New Zealand, and some districts of Victoria, but the truly enormous drifts of the Shoalhaven district in New South Wales must in the near future add largely to the world’s gold supply. ”

“ Everywhere else gold-mining is a comparatively hazardous and uncertain enterprise. Where the metal is found in alluvial deposits, the deposits usually vary much in the percentage of gold to the ton of soil which they yield, and they are usually exhausted in a few years. ”

“ The price of gold, which is itself the standard of value, could not rise to offset growing mining costs and to maintain profits, as was the case with iron, copper, and the other metals,—with the result that the margin of profit in gold mining became so small as materially to affect exploration and production. Another important cause of decreased production was the actual exhaustion of certain mines, and the lowering of the grades of ore available in many others. ”

“ Many gold mines have been abandoned as unprofitable that could have been mined at a profit had their owners been wealthy and enterprising enough to do a great deal of expensive prospecting by diamond drill, cross cuts, drifts and rises. In one instance that came to the writer's knowledge a clever mining engineer cleared nearly $200,000 profit by leasing for a term of years a gold mine that was supposed to be exhausted. A drill hole sunk less than 50 feet below the old workings revealed a pocket of ore in the vein, and paying quartz was found for many hundred feet below. ”

“ As the gold is found in quartz rock, and only to a small extent in gravel or other alluvial deposits, the mining requires capital, and will be carried on by companies. It will be carried on quickly, and so quickly with the aid of the enormously improved scientific appliances we now possess, as to exhaust at no distant period the mineral which the rocks contain. ”

“ There are a good many ways of gold-mining. Sometimes the mines are in veins in the hard rock. Then the miners bore down to them and dig out the rock, and break it up fine to get out the gold, just as they do silver. Another way is to find it in the loose sand in the bottoms of rocks and in gravel. When the miners first went out, they used to take a little gravel in a dish with some water, and shake it hard, so a little would slop over each time. ”

“ There is no rule as to the trend or strike of lodes, except that a greater number are found taking a northerly and southerly course than one which is easterly and westerly. At all events, such is the case in Australia, but it cannot be said that either has the advantage in being more productive. Some of the richest mines in Australasia have been in lodes running easterly and westerly, while gold, tin, and copper, in great quantity and of high percentage to the ton, have been got in such mines as Mount Morgan, Mount Bischoff, and the Burra, which contain no lodes properly so-called. ”

“ And, lastly, the sluice begat the jet, or hydraulicking proper, which is at present the highest effort of placer-mining. We thus reverse the primitive process which carried the wash-dirt to the water; we now carry the water to the wash-dirt. In California I found the miners washing down loose sandstones and hillocks of clay, passing the stuff through sluices, and making money when the gold averaged only 9d. and even 4d. to the ton. A man could work under favourable circumstances twenty to thirty tons a day. ”