 | 1907 - 1026 стор.
...its identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the district. Its hard ore...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | Geological Survey (U.S.) - 1907 - 532 стор.
...its identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the district. Its hard ore...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | 1907 - 532 стор.
...its identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the district. Its hard ore...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | Ernest Francis Burchard - 1910 - 248 стор.
...identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or drifts, is the best in the district. Its hard ore is also...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | Geological Survey (U.S.) - 1910 - 246 стор.
...identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or drifts, is the best in the district. Its hard ore is also...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | Ralph Arnold - 1910 - 958 стор.
...identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or drifts, is the best in the district. Its hard ore is also...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | 1916 - 1152 стор.
...trenches or drifts, is the best of the district. Its hard ore is also of high grade and has hitherto been for the most part held in reserve, since ore...thicker Big seam at a lower cost per unit of Iron. The seam lies only a few feet below the Big seam and has a thickness of 4 to 6 feet. Three samples from... | |
 | 1907 - 1200 стор.
...now nearly all mined out either by surface trenches ur CLINTON ORES OF BIRMINGHAM DISTRICT, ALABAMA. slopes, is the best in the district. Its hard ore...structure and composition of the Big and Irondale seams is shown in the following series of sections, taken at intervals of 2 to 5 miles apart along Red Mountain,... | |
 | 1909 - 822 стор.
...its identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the district. Its Hard ore...thicker Big seam at a lower cost per unit of iron. According to texture the Clinton ores are of two varieties, viz: (1) fossil ore and (2) oolitic ore.... | |
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Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the district. Its hard ore is also of high grade and hitherto has been for the most part held in reserve, since ore could be produced from the thicker Big seam... 