Economic geology
Encyclopedia
Economic geology is concerned with earth materials that can be used for economic and/or industrial purposes. These materials include precious and base metals, nonmetallic minerals, construction-grade stone, petroleum minerals, coal, and water. The term commonly refers to metallic mineral deposits and mineral resources. The techniques employed by other earth science disciplines (such as geochemistry
, mineralogy
, geophysics
, petrology
and structural geology
) might all be used to understand, describe, and exploit an ore deposit.
Economic geology is studied and practiced by geologists. However it is of prime interest to investment bankers, stock analysts and other professions such as engineers, environmental scientists, and conservationists because of the far-reaching impact that extractive industries have on society, the economy, and the environment.
deposits, which includes the study of ore genesis
and the processes within the Earth's crust that form and concentrate ore minerals into economically viable quantities.
Study of metallic ore deposits involves the use of structural geology
, geochemistry
, the study of metamorphism
and its processes, as well as understanding metasomatism
and other processes related to ore genesis.
Ore deposits are delineated by mineral exploration
, which uses geochemical
prospecting, drilling
and resource estimation via geostatistics
to quantify economic ore bodies. The ultimate aim of this process is mining
.
The study of sedimentology
is of prime importance to the delineation of economic reserves of petroleum
and coal
energy resources.
survey published in the American Geophysical Union
's international journal, Eos
, Earth scientists were asked whether global temperatures had risen since 1800 and if so, whether this was due to human influence. Overall, 90 percent of respondents agreed that temperatures have risen. Regarding causes, though 82 percent indicated that human activity was a 'significant contributing factor in changing mean global temperatures," less than half of economic geologists agreed.
Given that economic geoscientists had the lowest percentage of all Earth scientists surveyed, critic and author John Cook has claimed that "climate scepticism seems strongest among geologists closely linked to the mining and fossil fuel industries" and that this is due to the influence of their funding. In suggesting a rationale for climate change denial
, Cook noted a maxim by Upton Sinclair
: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."
The 2007 study's senior investigator, Dr. Peter Doran
, has noted as it relates to the findings that 'the American Association of Petroleum Geologists
has a public position statement formally rejecting the likelihood of human influence on recent climate.'
Geochemistry
The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and...
, mineralogy
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
, geophysics
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
, petrology
Petrology
Petrology is the branch of geology that studies rocks, and the conditions in which rocks form....
and structural geology
Structural geology
Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover information about the history of deformation in the rocks, and...
) might all be used to understand, describe, and exploit an ore deposit.
Economic geology is studied and practiced by geologists. However it is of prime interest to investment bankers, stock analysts and other professions such as engineers, environmental scientists, and conservationists because of the far-reaching impact that extractive industries have on society, the economy, and the environment.
Mineral resources
Mineral resources are concentrations of minerals significant for current and future societal needs. Ore is classified as mineralization economically and technically feasible for extraction. Not all mineralization meets these criteria for various reasons. The specific categories of mineralization in an economic sense are:- Mineral occurrences or prospects of geological interest but not necessarily economic interest
- Mineral resources include those potentially economically and technically feasible and those that are not
- Ore reserves, which must be economically and technically feasible to extract
Ore geology
Geologists are involved in the study of oreOre
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
deposits, which includes the study of ore genesis
Ore genesis
The various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are very dependent on the mineral or commodity....
and the processes within the Earth's crust that form and concentrate ore minerals into economically viable quantities.
Study of metallic ore deposits involves the use of structural geology
Structural geology
Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover information about the history of deformation in the rocks, and...
, geochemistry
Geochemistry
The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and...
, the study of metamorphism
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...
and its processes, as well as understanding metasomatism
Metasomatism
Metasomatism is the chemical alteration of a rock by hydrothermal and other fluids.Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact...
and other processes related to ore genesis.
Ore deposits are delineated by mineral exploration
Mineral exploration
Mineral exploration is the process of finding ore to mine. Mineral exploration is a much more intensive, organized and professional form of mineral prospecting and, though it frequently uses the services of prospecting, the process of mineral exploration on the whole is much more involved.-Stages...
, which uses geochemical
Geochemistry
The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and...
prospecting, drilling
Boring (earth)
Boring is drilling a hole, tunnel, or well in the earth.-Earth boring:Boring is used for a wide variety of applications in geology, agriculture, hydrology, civil engineering, and oil and natural gas industries...
and resource estimation via geostatistics
Geostatistics
Geostatistics is a branch of statistics focusing on spatial or spatiotemporal datasets. Developed originally to predict probability distributions of ore grades for mining operations, it is currently applied in diverse disciplines including petroleum geology, hydrogeology, hydrology, meteorology,...
to quantify economic ore bodies. The ultimate aim of this process is mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
.
Coal and petroleum geology
- See main articles CoalCoalCoal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
and Petroleum geologyPetroleum geologyPetroleum geology refers to the specific set of geological disciplines that are applied to the search for hydrocarbons .-Sedimentary basin analysis:...
The study of sedimentology
Sedimentology
Sedimentology encompasses the study of modern sediments such as sand, mud , and clay, and the processes that result in their deposition. Sedimentologists apply their understanding of modern processes to interpret geologic history through observations of sedimentary rocks and sedimentary...
is of prime importance to the delineation of economic reserves of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
and coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
energy resources.
Criticism
In a 2007 climate changeClimate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
survey published in the American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...
's international journal, Eos
Eos (journal)
Eos, Transactions, American Geophysical Union, a publication of the American Geophysical Union, is a weekly newspaper of geophysics that carries refereed articles on current research and on the relationship of geophysics to social and political questions, news, book reviews, AGU journal and meeting...
, Earth scientists were asked whether global temperatures had risen since 1800 and if so, whether this was due to human influence. Overall, 90 percent of respondents agreed that temperatures have risen. Regarding causes, though 82 percent indicated that human activity was a 'significant contributing factor in changing mean global temperatures," less than half of economic geologists agreed.
Given that economic geoscientists had the lowest percentage of all Earth scientists surveyed, critic and author John Cook has claimed that "climate scepticism seems strongest among geologists closely linked to the mining and fossil fuel industries" and that this is due to the influence of their funding. In suggesting a rationale for climate change denial
Climate change denial
Climate change denial is a term used to describe organized attempts to downplay, deny or dismiss the scientific consensus on the extent of global warming, its significance, and its connection to human behavior, especially for commercial or ideological reasons...
, Cook noted a maxim by Upton Sinclair
Upton Sinclair
Upton Beall Sinclair Jr. , was an American author who wrote close to one hundred books in many genres. He achieved popularity in the first half of the twentieth century, acquiring particular fame for his classic muckraking novel, The Jungle . It exposed conditions in the U.S...
: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."
The 2007 study's senior investigator, Dr. Peter Doran
Peter Doran
Peter Doran, Ph.D. is Professor of Earth and Environmental Sciences at the University of Illinois at Chicago.Doran specializes in polar regions, especially Antarctic climate and ecosystems. Doran was the lead author of a research paper about Antarctic temperatures that was published in the journal...
, has noted as it relates to the findings that 'the American Association of Petroleum Geologists
American Association of Petroleum Geologists
The American Association of Petroleum Geologists is one of the world's largest professional geological societies with over 31,000 members as of 2007. The AAPG works to advance the science of geology , to promote technology, and to inspire high professional conduct...
has a public position statement formally rejecting the likelihood of human influence on recent climate.'
See also
- Important publications in economic geology
- Mineral economicsMineral economicsMineral economics is the study of the business and economic aspects of natural resource extraction and use. Mineral economics involves studying topics in economic and financial analysis that are developed to meet the special needs of the natural resource industries...
- Mineral resource classificationMineral resource classificationMineral resource classification is the classification of mineral deposits based on their geologic certainty and economic value.Mineral deposits can be classified as:...
- OreOreAn ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
- Ore genesisOre genesisThe various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are very dependent on the mineral or commodity....
- CoalCoalCoal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...