Geology and the extraction of natural resources

The study of Earth and its geological processes is essential to the discovery, extraction, and management of natural resources, from minerals to energy resources.

Background

Geology is the study of the planet Earth: its composition, origin, and history, and the environmental, biological, chemical, and physical forces outside and within it. As a science, geology grew from the nineteenth century study of natural features, stratigraphy, and fossils in outcroppings to a wide variety of scientific subspecialties covering myriad aspects of the planet. Since the early nineteenth century, geology has involved accurate mapping of the Earth’s topography and discovery, study, and exploitation of major deposits around the world.

A guiding principle in geology has been uniformitarianism: geological processes that are observed today are the same as those that occurred in the past and those that will occur in the future. Application of this concept on a planetary scale allows scientists to prospect for minerals using remote-sensing techniques.

Catastrophic events, including meteor impacts, have been deduced from geological deposits and have been credited with causing widespread mass extinctions observed in the fossil record. Identification of the large meteor impact responsible for forming Chesapeake Bay has provided an explanation for recent earthquakes in the region and for the presence of saltwater aquifers in Virginia. Some economic geologists have postulated that the platinum deposit at Sudbury, Ontario, is a meteor impact site from billions of years ago.

The United States Geological Survey (part of the Department of the Interior) is the governmental agency responsible for producing official maps and reports. Most other nations have similar agencies, including the Geological Survey of Canada, Servicio Geológico Mexicano, the British Geological Survey, Geoscience Australia, the Geological Survey of Japan, and the South Africa Council for Geoscience, which all host informational Web sites.

Knowledge of geology is fundamental to the understanding of all inanimate resources on Earth. energy can provide an inexpensive alternative to fossil and nuclear sources for generating electricity. Discovery of necessary mineral resources is a prerequisite to exploitation, while the mechanics of exploiting those resources also requires geological expertise. Environmental geologists are involved in mapping and investigating toxic contamination areas for possible mitigation. Search for permanent geological sites for radioactive materials is going on in countries around the world. Potential natural hazards—including unstable topography, earthquake fault lines, and volcanic activity—require geological monitoring to warn people of impending disasters.

Exploration Geology

Exploration geologists focus on the discovery and exploitation of mineral and deposits and fossil fuels. Age humans found outcroppings of flint and chert with which to make arrowheads and other tools. Eventually, humans moved on to easily worked metals such as copper, tin, silver, gold, and iron. Precious gems have been highly valued for millennia, and new sources for these ores and minerals continue to be found.

Modern industrialized society requires metals for basic construction and manufacturing. The increasing technological demand has moved geological exploration from the California gold rush era of the American West to the worldwide search for uranium for nuclear weapons to the search for rare earth elements for high-tech electronics and lithium deposits for batteries. Geologists in the twenty-first century rarely engage in time-consuming initial field exploration and prospecting, relying on from aircraft and satellites to determine where new mineral deposits might be found. Confirmation of mineral deposits and plans for exploitation require geological expertise.

The exploitation of coal, oil, and gas deposits around the world provides vital sources of energy to the billions of people on Earth. Most geologists are employed, usually by governments and private industry, in this aspect of geology.

Coal remains the most important fuel for electric power production worldwide, with of anthracite (“hard”) and bituminous (“soft”) coal widespread in North America, Europe, and Asia. Large-scale underground coal mining is labor intensive and expensive. Many American coal companies have opted to use cheaper methods of obtaining coal, such as and Mountaintop removal mining (MTR), in which coal deposits are located at or near surface level. MTR in areas like West Virginia and Kentucky is unpopular with the general public because of the widespread environmental degradation that occurs when entire mountains are leveled and (soil and non-coal rock) materials are placed in adjacent valleys. Land use after MTR may be determined by geological studies; the areas are usually left unvegetated after mining activities end. Coal impoundments are used to hold huge amounts of MTR coal waste, and if the impoundment fails, aquatic wildlife in the area’s streams and rivers is eradicated. In March, 2009, the U.S. Environmental Protection Agency announced that permits for MTR of coal would be carefully scrutinized.

Oil deposits occur around the world, and geological exploration teams continue to find major discoveries. Exploration and development of new oil fields are often complicated by politics, on both national and international scales. Opening up the Alaskan National Wildlife Reserve (ANWR) to oil exploration and drilling is an example of such complications. Even though President George W. Bush and Vice President Dick Cheney both strongly favored drilling, Congress was unwilling to authorize oil leases in the eight years (2001-2009) of the Bush presidency. In the 2008 U.S. presidential election, ANWR became a major campaign issue when Alaskan governor Sarah Palin, who was the Republican vice presidential candidate, strongly endorsed drilling.

Discovery and commercial exploitation of heavy oil sands, which cannot be pumped out of the ground like deposits, have become major political issues because this leaves a large carbon footprint. Oil sands are strip-mined or hauled from massive open-pit mines. An estimated 780,000 barrels of oil are produced per day from Canadian oil sands in Alberta, and about 60 percent of this is exported to the United States. Oil sands in Alberta are estimated to contain more than one trillion barrels of oil, 80 percent of which is not accessible through present surface mining methods. Oil sand deposits also occur in Utah, Venezuela, and Russia.

Geological Monitoring of Volcanoes and Earthquakes

The devastating Boxing Day tsunami of December 26, 2004, which engulfed Indian Ocean shorelines from Indonesia to East Africa and killed more than 225,000 people, followed an undersea event known as the Great Sumatra-Andaman earthquake. The countries most affected by the tsunami lacked geological monitoring stations. Such a seismological monitoring network could have provided many areas with several hours warning of the impending tsunami and lessened the death toll. The U.S. National Oceanic and Atmospheric Administration operates the Pacific Tsunami Warning System, which warns of potential problems for Hawaii, Alaska, and the Pacific coast of North America.

Volcano monitoring is necessary to warn people of impending eruptions. Erupting volcanoes emit clouds of ash that can be sucked into jet aircraft engines, where the ash liquefies and then deposits a solid glass coating to the rear of the jet turbine. This glass coating interferes with the jet enough to cause the aircraft to crash. Ash problems necessitate closure of airports within the reach of the erupting volcano, and aircraft must be diverted from routes that pass through the ash clouds.

Environmental Geology

Environmental geologists use a variety of geological, geochemical, microbiological, and hydrological techniques to identify and mitigate hazards resulting from urban sprawl, industrialization, and mining activities. The most common environmental problems include and contamination, dumping of hazardous wastes in unprotected ground, and air pollution related to improper waste handling.

A permanent geological storage site for reactor waste in the United States has been a limiting factor in public support for the nuclear power industry. (Nuclear weapons waste is stored in Carlsbad, New Mexico.) Requirements for geological storage include the absence of groundwater and total lack of seismic activity in a solid bedrock formation. Many locations have been proposed. In 1987, Yucca Flat, Nevada, was selected, but the selection met with almost immediate opposition because of unanswered geological questions. In March, 2009, President Barack Obama announced that plans to use Yucca Flat had been abandoned. Stephen Chu, the secretary of energy for the Obama administration, indicated that the United States might build nuclear power reactors that could utilize nuclear waste, thus dramatically lessening (but not eliminating) the amount of radioactive waste requiring permanent storage. Other countries, including Sweden, have conducted rigorous nationwide geological surveys to identify potential nuclear waste storage sites and are moving closer to final site selection. Some nuclear industry experts believe that the United States will not select a site until 2030.

Commercial Power Production from Geothermal Energy

Harnessing hot springs and geysers to produce electricity has been going on at Larderello, Italy, for more than a century and is well established in Iceland and the Philippines; the latter two countries produce about 20 percent of their electricity from geothermal energy. Iceland has a geothermal capacity of 779 megawatts as of 2020. There are eighteen electricity plants at The Geysers, in Northern California. Important geological concerns arise when harnessing geothermal sources. The major problem at generating locations like Wairakei, New Zealand, and The Geysers is local depletion of heat sources; heated zones are tapped too intensively for too long of a period to allow recharge of heat from deep within the Earth. Other problems include the need for drilling deep wells and for fracturing rock around the deep wells at geothermal locations. Although the technology for drilling deep wells exists, it is a costly process.

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