![]() Mining operations were carried on by stock companies incorporated in various states-New York, Vermont, Ohio, Michigan, and Illinois were among those represented. One 1846 guide to the mines presented a commonly held belief: To this impetus could be added the boom spirit of the time, an abundance of venture capital, and a highly unrealistic estimate of the ease by which fortunes could be acquired through copper mining. The presence of copper on Isle Royale was a matter of common knowledge by 1843, with information ranging from Jesuit accounts and tales of American Fur Company fishermen to formal geological reports. In 1846, however, a rush began that reached its peak the following year, then rapidly declined and came to an end in 1855. A few mineral locations were filed in 1843 under permit from the War Department however, the main rush did not begin until 1846, partly because of the more accessible deposits on the mainland, partly because of an erroneous belief that mining rights under the existing mining laws did not extend beyond the south shore of Lake Superior. Previously the only white men living on the island were seasonal fishermen, using the fish houses erected by the American Fur Company between 18. Because they normally don’t follow a trend, they are hard to plan for.The first mining explorations on Isle Royale began in 1843, after the Chippewa Indians relinquished claim to the island under a treaty of that year. Planning and mitigation: When mining the Springfield and Herrin coals, miners can be made aware of what coal balls are and what they look like. Coal balls (brown masses) in an underground coal mine in the Amburgy coal bed, eastern Kentucky, and details of samples showing permineralized woody tissue (brown) in coal (black). 11) coal beds (Krausse and others, 1979 Nelson, 1983). They are most common in the Springfield (W. Known Kentucky occurrences: Coal balls are very rare in eastern Kentucky mines, but many have been reported in western Kentucky (Greb and others, 1999). In at least one case, coal balls were encountered near a sandstone paleochannel (cutout) margin, so might have followed the channel trend (Greb and others, 1999). Trends: Most coal-ball occurrences do not follow predictable trends however, concentrations of coal balls generally only occupy small areas, so if they do pose a local obstacle, they can usually be easily bypassed. Coal balls can also be associated with cutouts and roof rolls (paleochannels), which are discussed separately. ![]() Isolated rock masses can also occur in mine roofs, but are discussed under Concretions. Potential roof-fall hazards: Coal balls occur in coal seams and not roof rocks, so are not roof-fall hazards. ![]() Encountering large coal-ball masses during mining is similar to mining through limestone. In surface mines, large coal-ball masses or concentrations may need to be blasted (see, for example, Nelson, 1983). Photograph courtesy of John Popp.ĭiscontinuities and obstacles: Individual small coal balls can be mined through without significant issue, but larger coal balls or concentrations of coal balls can slow mining, because they are hard and wear down bits on continuous-miner machines. The coal balls have a brown to reddish hue, and are locally termed "red rock." The blue band is a regional parting in the coal. Small coal balls concentrated in the Herrin coal bed in an underground mine. Typical appearance of coal balls (brown masses) in an underground coal mine in the Springfield (Western Kentucky No 9) coal bed in Kentucky. In the Illinois basin, coal balls are commonly pyritized, and sometimes stained red from iron, so are sometimes termed “red rock.” Silica-rich coal balls have also been reported in a southern Illinois coal mine and may occur in western Kentucky (Nelson, 1983). In one eastern Kentucky mine, an operator reported finding “real wood” in a seam, which turned out to be well-preserved fossil wood in a coal ball. Individual coal balls can be inches to many feet in diameter, and coal-ball clusters may occupy a small part (concentrated along the top or bottom) or the entire height of a seam. They are formed in the original peat before it undergoes coalification (DeMaris and others, 1983 Scott and others, 1996). Definition and formation: Coal balls are calcareous masses of fossil peat found in coal beds.
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