Earth’s Geosphere: Composition, Minerals, and Resources
The Geosphere: Earth’s Solid Layers
The geosphere is generally a solid layer, although in some areas it may be molten due to high internal temperatures. It consists of rocks, minerals, and metals. The geosphere has three main layers:
- Crust: The outermost solid layer, with a thickness of 27 to 70 km on continents and 6 to 18 km under the oceans.
- Mantle: The intermediate layer, composed of rocks, extending from the crust to a depth of 2,900 km.
- Core: The deepest layer, consisting of an iron-nickel core with external and internal parts.
Minerals: Composition and Properties
Minerals are different materials found in crustal rocks. A mineral is a substance composed of one or more elements or a chemical compound formed through terrestrial processes, such as a volcanic eruption. Minerals have a definite composition, containing one or more elements. The eight most abundant chemical elements are oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium. Oxygen and silicon are the most frequent, often forming silicates with other elements. Non-silicate minerals are formed by two or more chemical elements, such as iron, oxygen, sulfur, or calcium, or by a single element, known as native elements like silver.
Types of Minerals
- Silicates: Quartz
- Carbonates: Calcite
- Sulphates: Gypsum
- Oxides: Oligist and Magnetite
- Sulphides: Pyrite
- Native Elements: Sulfur, gold, platinum, and diamond
Physical Properties of Minerals
Minerals are characterized by properties such as hardness, cleavage, color, brightness, and clarity.
Rocks: Formation and Types
Rocks are formed and continually transformed through various processes. There are three main types of rocks:
- Sedimentary
- Metamorphic
- Magmatic
Metamorphic rocks are formed when sedimentary or other metamorphic rocks are transformed under high pressure and temperature inside the Earth.
Useful Minerals and Their Extraction
Useful minerals are extracted from ore deposits, such as metalliferous ores. Many minerals are raw materials used to obtain useful products. For example, sulfur is used in fertilizers, and gypsum is used in plaster.
Minerals in Jewelry and Industry
Minerals of great beauty and hardness, such as emeralds, diamonds, and sapphires, are used in jewelry. Native gold, silver, and platinum are also used. Industrial rocks, such as those used in building materials like brick, ceramics, and tiles, are also valuable. Ornamental rocks include granite and marble.
Geosphere Resources: Fossil Fuels
The geosphere also contains fossil fuels:
Coal
Coal is used as fuel for energy production. It is formed from plant debris buried in sediments in rivers and lakes, transformed by bacteria through a process called carbonization.
Oil
Oil is a black, oily liquid. Propane, butane, gasoline, and plastics are extracted from it. Tar and oil originate from marine organisms buried in sediments deep in the sea.
Risks of Resource Exploitation
The exploitation of resources carries risks, including health risks and environmental hazards. The use of fossil fuels produces gases that pollute the atmosphere, causing acid rain and global warming. Oil spills cause ecological disasters, preventing light from reaching algae in the sea. Industrial processing of resources can damage the environment, such as toxic water contaminating groundwater and surface water.
Solutions for Sustainable Resource Use
To address these problems, we must move towards the sustainable exploitation of resources that are environmentally friendly and contribute to the sustainable development of society. Saving energy and using renewable raw materials are crucial in the 21st century.