Economic Mineral Resources

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<p>The category of economic mineral resources includes both industrial minerals and fossil fuels. The abundance of these resources in Ohio has been of profound had a big influence in the economic development of the state and its continued prosperity. In total, these resources have an annual value of more than 2.5 billion dollars. </p>
<h2>Fossil Fuels</h2>
<p>The first European settlers in Ohio recognized the presence of coal in natural outcrops in stream and river banks in the eastern part of the state. As the industrial revolution began, Ohio’s coal resources became increasingly important. One of the primary objectives of the first Geological Survey of Ohio in 1837-1838 was to survey the mineral resources of the state, particularly coal. Soon, coal was being mined as a fuel to heat homes and businesses. Development of the Ohio canal system in the 1830s and 1840s permitted easy transport of coal from mines to markets. By the mid 1800’s, railroads began to replace the canals, allowing for faster and more efficient delivery of coal to consumers. By the late 1800’s, mechanization and improvement of mining methods led to a steady increase in the production of Ohio coal. Much coal was used to make coke to fuel the many steel mills that dotted the upper Ohio River valley. Eventually, coal became the primary source of energy to generate electricity and the dominant underground mines were replaced by surface strip mines, where large amounts of overlying rock was removed by massive shovels and draglines drag lines to get access to the valuable coal seam. </p>
<p>Currently, there are about 90 active coal-mining operations in 15 eastern Ohio counties that produce coal worth about $626 million annually. In recent years there has been a trend to return to underground-mining methods, particularly long-wall mining. With this technique, almost all of the coal is recovered for sale in contrast to the older room-and-pillar method where up to half the coal remained in the ground to support the roof of the mine. The leading coal-producing counties in decreasing order are Belmont, Harrison, Tuscarawas, Athens, and Jefferson. Although there are about 50 named coal beds or seams in Ohio, only a few are of sufficient thickness and extent to be mined. Most production comes from the Pittsburgh (No.8) coal seam.</p>
<p>Coal formed in Ohio during the Pennsylvanian Period about 300 million years ago when the state was near the equator with a warm climate. Eastern Ohio was a low-lying coastal area that was crossed by delta-building streams from the rising Appalachian Mountains to the east. Vast swamps with lush vegetation dominated the coastal areas. As the vegetation died and fell into the oxygen-poor waters of the swamps, it became thick layers of peat that eventually were compressed and buried under shale and sandstone as rivers switched course. As more rock accumulated above the swamp vegetation, it became compressed and altered first to lignite, or brown coal, and eventually to bituminous coal.</p>
<p>Although Ohio is not a major producer of petroleum (oil) and natural gas on a global or national scale, the state has long had important production of these commodities. Soon after Col. Edwin L. Drake’s famous first oil well in 1859 in Titusville, Pennsylvania, drilling began in adjacent areas in Trumbull County in northeastern Ohio and in Washington County in southeastern Ohio. Although Drake’s well is recognized as the first well drilled specifically for oil, a well drilled for salt brine in 1816 in Noble County, Ohio, struck oil, which was sold as a topical medicine for humans and animals, as a lubricant, and as lamp fuel. </p>
<p>In 1884, natural gas and oil were discovered in northwestern Ohio and an oil boom began. Soon, the area was overrun with drillers seeking oil and wooden derricks dotted the landscape, some almost on top of one another. Several major oil companies got their start in this oil field, which is commonly regarded as the first giant field in the United States. Abundant natural gas associated with the oil was vented and set on fire. This wasteful practice soon resulted in the exhaustion of natural gas from the field and the depressurization of the reservoir so that much, perhaps the majority, of the oil remains in the ground. The oil was derived from the Trenton Limestone of Ordovician age and is sometimes referred to as the Trenton Field.</p>
<p>Edward Orton, professor of geology at Ohio State University and State Geologist of Ohio, devoted much study to the occurrence of oil and gas in the Trenton Field and published extensive reports on the topic. Many drillers and investors thought that these hydrocarbons were being created anew in the rocks below and that the supply would be inexhaustible. Orton pointed out that the deposits were finite and accumulated only under certain conditions. Communities such as Findlay offered free gas to any industry that would relocate to the community and many glass plants and other energy dependant dependent industries took advantage of the offer. However, the wasteful practice of venting gas to the atmosphere soon resulted in a natural-gas shortage in the area, just as Orton had predicted.</p>
<p>Since the beginning of production in Ohio, at least 1.1 billion barrels of oil and 8 billion MCF (thousand cubic feet) of natural gas have been produced. Drilling activity and production vary depending on the price of oil and gas, but recent data indicate more than 700 wells drilled annually in 47 counties, mostly in eastern Ohio. More than 300 of these wells were drilled to the Silurian “Clinton-Medina” unit. Annual value of oil was nearly $300 million and $760 million for natural gas. </p>
<p>Petroleum and natural gas are the chemically altered remains of microscopic plants and animals that lived in considerable abundance in ancient seas. As these remains settled with sediment to the bottom of oxygen-poor seas and were buried beneath thick layers of sediment, hydrocarbons (hydrogen and carbon) were altered to waxy kerogen in black shales shale such as the Ohio Shale. As the rock became more deeply buried and warmer, oil began to form from the kerogen at about 90 degrees C and then to natural gas at about 160 degrees C. Temperatures above 250 degrees C destroyed the oil and gas. This temperature range is known as the Oil Window. Later, the oil and gas may flow from the source rock to a reservoir rock where it may be trapped between the sediment grains and discovered and produced by oil and gas companies.</p>
<h2>Industrial Minerals</h2>
<p><strong>Limestone and Dolomite</strong></p>
<p>Traditionally, Ohio ranks fourth in the nation in production of carbonate rocks and limestone and dolomite account for more than half of the annual value of industrial minerals produced in the state. They are quarried in 48 counties, annually producing 79 million tons valued at $471 million. Most of the limestone and dolomite produced in Ohio is used for construction aggregate for roads and building projects and an aggregate in concrete and asphalt. However, these commodities are an important source of agricultural lime, a fluxing agent used in making steel, cement, building stone, and many uses in the chemical industry. </p>
<p><strong>Sand and Gravel</strong></p>
<p>Sand and gravel deposits are abundant in Ohio and are primarily a result of deposition deposits formed by running water during the Pleistocene Ice Age. The terms sand and gravel refer to size of the grains of the materials rather than their composition. The generally rounded grains are rock fragments of sedimentary, metamorphic, and igneous rocks. The latter two categories represent rocks transported by glaciers from Canada and deposited in Ohio as the ice melted. Large volumes of meltwater melt water from the glaciers filled river valleys with sand and gravel in deposits known collectively as outwashout wash. Some sand and gravel deposits formed in subglacial sub-glacial tunnels (eskers) or in holes in the ice or along the ice edge as conical hills (kames). These loose, unconsolidated materials are easily mined in open-pit surface mines.</p>
<p>Ohio ranks sixth nationally in sand and gravel production and produces 52 million tons annually, valued at $247 million. These deposits are mined in 64 Ohio counties, including deposits dredged from the bed of Lake Erie. Ohio is fortunate to have such widespread abundance of these commodities as transportation costs are greatly reduced if the deposits are close to their point of use. Most sand and gravel is used for construction in road-base material, as an aggregate in concrete and asphalt, glass making, and molding sand for casting iron and aluminum. Sand and gravel deposits are important aquifers for ground water.</p>
<p><strong>Sandstone and Conglomerate</strong></p>