3907 x 2561 px | 33,1 x 21,7 cm | 13 x 8,5 inches | 300dpi
Data acquisizione:
8 febbraio 2012
Altre informazioni:
Vermilion Range exists between Tower and Ely, Minnesota, and contains significant deposits of iron ore. The Vermilion, along with the Mesabi and Cuyuna Ranges, constitute the Iron Ranges of northern Minnesota which were deposited in the Animikie Group. While the Mesabi Range had iron ore close enough to the surface to enable pit mining, mines on the Vermilion and Cuyuna ranges tended to be deep underground. The Soudan mine was nearly 1/2 mile underground and required blasting of Precambrian sedimentary bedrock Despite the effort needed for the deep mining Soudan mine, the ore obtained was worth the effort; the quality of the hematite ore was so pure that two pieces could be welded. The bedrock, known as taconite, also contained iron, but in a much lower concentration. After more efficient practices for creating steel were discovered, the high-quality ore was abandon due to its more costly mining expense. New processes were developed to extract the iron from the taconite, using open-pit mining, that made the ore available at a significantly reduced cost. This was successful, and Minnesota's iron industry centered on the Mesabi Range, where the taconite was much easier to access
