Question: What elongate trend containing deposits of iron ore is in Marble, Minnesota?
Context: Iron ore is rock containing traces of metallic iron, which can vary in color from grey, yellow, or purple to red.  Iron in these rocks iron is most commonly found in the form of magnetite (FeO), hematite (FeO), goethite (FeO(OH)), limonite (FeO(OH)·n(HO)) or siderite (FeCO).  Roughly 98% of iron ore on the global market is used in steel production... Common methods of extracting the iron ore consist of blasting, drilling, or general excavating.  After the iron ore is out of the ground, the next step in the production phases is called beneficiation, which is usually carried out by dissolving rock material around the iron in order to obtain the mineral.  Once iron is in its purest form, it is then shipped to global markets via truck, boat, or train.  The activities of iron ore mining projects, from excavation to beneficiation to transportation, span across various landscapes, inflicting residual effects on various aspects of the natural environment in the process, The Rowghat Mines contain the largest iron ore deposits in Chhattisgarh India after the Bailadila Iron Ore Mine.  Rowghat Mines' reserves have been assessed at 731.93 Mn Tonnes.  Bailadila has reserves assessed at 1.343 Bn Tonnes.  Iron ore deposits in Rowghat were discovered in 1899 and in 1949 Geological Survey of India investigated the area. The discovery of a boulder of high-grade iron ore by Leonidas Merritt in 1887 during a survey for the railroad, which he brought to Duluth, the Merritt brothers ("the Seven Iron Men") established the Mountain Iron Mine in 1892 Mountain Iron, Minnesota which represents the beginning of the exploitation of the Mesabi Range iron ore in the Iron Range of northeast Minnesota.  By 1893 the Merritts had claims on a significant portion of the Mesabi Iron Range and had built the Duluth, Missabe & Northern Railway DM&IR.  Financial conditions forced them sell their shares to John D. Rockefeller who later sold to Andrew Carnegie.  The early development was as an underground mine, but open cast mining soon proved to be a better choice because of the soft, shallow ore deposits.  The Mesabi Range and nearby Vermilion Range led Minnesota to become the nation's largest producer of iron ore and the United States to lead the world in steel production.  This capacity is considered to have been a major factor in America's ability to contribute to World War II.  It also played a major role in the financial success of Andrew Carnegie and U.S. Steel.  Carnegie returned some of his fortune to the communities by funding 2500 public Carnegie Libraries across the country, including 64 in rural Minnesota. The Mesabi Iron Range is an elongate trend containing large deposits of iron ore, and the largest of four major iron ranges in the region collectively known as the Iron Range of Minnesota.  Discovered in 1866, it is the chief iron ore mining district in the United States.  The district is located in northeast Minnesota, largely in Itasca and Saint Louis counties.  It was extensively worked in the earlier part of the 20th century.  Extraction operations declined throughout the mid-1970s but rebounded in 2005.  China's growing demand for iron, along with the falling value of the U.S. dollar versus other world currencies, have made taconite production profitable again, and some mines that had closed have been reopened, while current mines have been expanded. The Vermilion Range exists between Tower and Ely, Minnesota, and contains significant deposits of iron ore.  Together with the Mesabi and Cuyuna Ranges, these three constitute the Iron Ranges of northern Minnesota; they were deposited in the Animikie Group.  While the Mesabi Range had iron ore close enough to the surface to enable pit mining, mines had to be dug deep underground to reach the ore of the Vermilion and Cuyuna ranges.  The Soudan mine was nearly 1/2 mile underground and required blasting of Precambrian sedimentary bedrock. El Cerro Mutún (Spanish for "the Mountain Mutún") is an iron ore deposit.  Located in the Germán Busch Province in the Santa Cruz Department of Bolivia, near Puerto Suárez, it extends across the border into Brazil, where it is called the "Serrania de Jacadigo".  Also known as the ""Serrania Mutún"", it has an area of about 75 square kilometers.  Its estimated reserves are about 40.205 billion (40.205 × 10) tons of iron ore of 50% iron, mainly in hematite and magnetite form, and in lesser quantities in siderite and manganese minerals.  This can be compared with an estimate of the total world reserves of iron ore: 800 billion tons of crude ore containing more than 230 billion tons of iron. The Ruoutevare Iron Deposit is one of the largest known unexploited iron ore deposits in Sweden.  Located in Kvikkjokk in Norrbotten County, Lapland, the deposit was discovered in the early 1970s by the Geological Survey of Sweden and found to have between 116 and 123 million tonnes of iron ore.  In 2008 Beowulf Mining announced a maiden JORC compliant resource estimate for Ruoutevare with an inferred mineral resource estimate of 140 million tonnes of iron ore at a grade of 39.1%, with 5.7% titanium and 0.2% Vanadium Bukit Besi is a small mining town in Dungun constituency, Terengganu, Malaysia famous for its high quality iron ore.  The ferum content of Bukit Besi's iron ore is more than 70% hence making it a very high grade sought after iron ore and is Malaysia's best known grade of iron ore.  The iron ore reserve was discovered by the British during the colonial era.  More than 90% of Bukit Besi's iron ore reserves have already been mined by colonial powers Britain and Japan in the 1900s.  It is estimated that roughly 50 million metric tonnes of iron ore deposits remain as of today.  Recent events have seen the Terengganu state government awarding iron ore mining concessions to China-based companies such as Eastern Steel and Shougang Steel whom together with their local Malaysian partners will mine the remaining iron ore reserves in Bukit Besi over the span of 25 years hence providing a new lease of economic opportunities for locals in the area. Hill-Annex Mine State Park is a state park of Minnesota, United States, interpreting the open-pit mining heritage of the Mesabi Range.  The park is located in the city of Marble, and just outside the adjacent city of Calumet, both in Itasca County, Minnesota.  The park provides access to fossil material exposed by mining from the Cretaceous era Coleraine Formation. Iron mining in the United States produced 42.5 million metric tons of iron ore in 2015, worth US$3.8 billion.  Iron ore was the third-highest-value metal mined in the United States, after gold and copper.  Iron ore was mined from nine active mines and three reclamation operations in Michigan, Minnesota, and Utah.  Most of the iron ore was mined in northern Minnesota’s Mesabi Range.  Net exports (exports minus imports) were 3.9 million tons.  US iron ore made up 2.5 percent of the total mined worldwide in 2015.  Employment as of 2014 was 5,750 in iron mines and iron ore treatment plants.
Answer: Mesabi Range