Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 26, 2025
The ore of the Deer Trail forms a thinner sheet containing considerable copper, and sometimes two hundred to three hundred dollars to the ton in silver. The rocks which hold these ore deposits are of Silurian age, but they received their metalliferous impregnation much later, probably in the Tertiary, and subsequent to the period of disturbance in which they were elevated and metamorphosed.
After whole mountains have passed through this grinding mill, and have been washed by the hand of nature, the residue becomes metalliferous, and man finds it worth his while to complete the task of separation. Bad as the above treatment of the miners appears, it is gladly accepted of by them; for the condition of the labouring agriculturists is much worse.
In every direction are seen the hollows made by the miners of ancient days, the white colour of the granite veined with the darker metalliferous streaks, and the curious shape of the rocks formed by the streams flowing down its sides, give it a remarkably picturesque appearance. The machinery used for crushing the rock is set in motion by these streams.
Each "gunner" seized his trip, and as the leader shrieked his signal the six ponderous masses of metalliferous rock heaved into the air as one. But they did not strike their objective, for as the signal was given, Stevens shot power into his projectors.
What their mineral wealth may be, remains for European investigation; but gold has been found in their rivers, and from the various heights of their hills, we may fairly suppose them, in some instances at least, metalliferous.
In several spots of the valley of Caracas, the gneiss contains a small quantity of gold, disseminated in small veins of quartz, sulphuretted silver, azure copper-ore, and galena; but it is doubtful whether these different metalliferous substances are not too poor to encourage any attempt at working them.
The quarrying of quartz rock differs little from the quarrying of other metalliferous vein-stones. The lode descends steeply, and the excavation must follow its course. Sometimes the quartz is so soft that it may easily be loosened with the pick. The harder rock is blasted. Soft quartz is that which is penetrated by numerous cavities, though the lumps between the cavities may be very hard.
A tunnel has been formed at the bottom of the mine through which the waters flow after they have performed their task, which also carries away the crushed granite, while the heavier metalliferous substances are precipitated into the troughs.
Sometimes the plane of junction between two contiguous sheets of rock has been the channel through which has flowed a metalliferous solution, and the zone where the ore has replaced by substitution portions of one or both strata. These are often called blanket veins in the West, but they belong rather to the category of contact deposits as I have heretofore defined them.
This formation is intersected by numerous metalliferous veins, running, though irregularly, N.W. and S.E., and generally at right angles to the many dikes. The veins consist of native silver, of muriate of silver, an amalgam of silver, cobalt, antimony, and arsenic, generally embedded in sulphate of barytes.
Word Of The Day
Others Looking