Economic Geology: Minerals and Materials
Introduction
Economic geology is the study of materials that the earth produces, which is useful to human beings. The study involves identifying minerals and rocks, their origins, how they are formed, and how they can be mined and used. Economic geologists seek to understand how metals, minerals, and energy resources can be extracted from the earth’s crust, evaluating their economic viability.
Key Concepts
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Mineral Resources: Minerals are the building blocks of rocks, and they are the foundation of economic geology. They are natural substances that have a distinctive chemical composition and physical properties. A mineral resource is a concentration of a mineral that can be extracted and processed profitably.
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Types of Mineral Deposits: Mineral deposits can be classified based on their origin or geological environment. They are often found in veins, bodies, or scattered in rock formations. Some of the common types of mineral deposits include:
- Igneous Deposits: these are formed from cooling of molten lava or magma. Examples of minerals found in igneous deposits include copper, gold, and nickel.
- Sedimentary Deposits: these are formed from sedimentary rocks, including shale, sandstone, and limestone. Examples of minerals found in sedimentary deposits include bauxite and phosphate.
- Metamorphic Deposits: these are formed from intense heat and pressure, causing changes in existing rocks. Examples of minerals found in metamorphic deposits include marble, graphite, and garnet.
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Extraction of Minerals: The extraction of minerals involves several steps, including exploration, drilling, blasting, and hauling. Minerals can be extracted using several methods, including open-pit mining, underground mining, and placer mining.
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Economic Viability: When evaluating mineral deposits, economic viability is a crucial factor. The economic viability of a mineral deposit depends on several factors, including the mineral’s market price, the cost of extraction, and the environmental impacts of mining.
Relevant Equations and Formulas
There are several equations and formulas used in economic geology. Here are some of the most common ones:
- Grade of Ore = (Amount of metal in ore/Amount of rock in ore) x 100%
- Mining Recovery = (Amount of metal in ore after mining/Amount of metal in ore before mining) x 100%
- Strip Ratio = Amount of waste rock/Amount of ore
- Net Smelter Return = (Amount of metal sold x Price per unit of metal) – Smelting Cost – Refining Cost
Examples
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Copper: Copper is one of the most widely used metals in the world. It is used in electrical wiring, plumbing, and construction. Copper is often found in igneous deposits, such as porphyry copper deposits. Chile is the world’s largest producer of copper.
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Gold: Gold is a precious metal that has been used for centuries as currency and jewelry. It is often found in sedimentary and metamorphic deposits. South Africa is the world’s largest producer of gold.
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Coal: Coal is a fossil fuel that is used for electricity generation and industrial purposes. It is often found in sedimentary deposits, such as coal seams. China is the world’s largest producer of coal.
References for Further Learning
Here are some useful resources for those who want to learn more about economic geology:
- Economic Geology journal
- Society of Economic Geologists
- U.S. Geological Survey – Mineral Resources Program
- Colorado School of Mines – Economic Geology Program
Conclusion
Economic geology plays an essential role in identifying and extracting minerals and materials that are useful to human beings. Understanding the key concepts, equations, and formulas can help identify mineral deposits that are economically viable. With technological advancements in mining and extraction, the future of economic geology looks bright.
