Press enter after choosing selection

Mining Under Difficulties

Mining Under Difficulties image
Parent Issue
Public Domain
OCR Text

The altitude of the Stevens mine on Mount McClellan is 12,500 feet. At the depth of from 60 to 200 feet the crevice matter, consisting of süioa, calcite and ore, together with the surrounding wall rock, is a solid frozen maas. McClellan is one of the highest eastern spurs of the snowy range ; it has the form of a horseshoe, with a bold escarpment of feldsparthic rocknearly 2,000 feet high; which in some places is nearly perpendicular. Nothing unusual occura until a distance of some 80 or 90 feet had been made ; then the frozen territory war reached, and it has continued for ovea 200 feet. There are no indications of e thaw, snmmer or winter. The whol frozen territory is surrounded by hard' ma&sive rock, and the lode itself is as hard and massive as the rock. The miners, being unable to excávate the frozen material with a piek or drill, f ound that the only way was to kindie a large wood fire at night against the back end of the tunnel, and in the morning take out the disintegrated ore. This has been the mode of mining for more than two years. The tunnel te over 290 feet deep, and there is no diminution to the frost. There is, so far as can be seen, no opening or channel through which the frost could reach such a depth from the surface. There are no other mines in the same vicinitv in a like frozen state. The theory is that the rock was laid down in glacial times, when there was cold enough to freeze the very earth's heart. In that case the mine is an ice-house whose stores have remained unthawed for at least 80,000 years ! The phenomenon is not uncommon or inexplicable when openings can be found through which a current of air can pass ; but cases which, like the Brandon frozen well and the Stevens mine, show no way for air currents, are stül referred to imbedded icebergs and the glacial period.


Old News
Michigan Argus