Natural Resources and Geological Processes Explained
Natural Resources
Renewable resources: Components of nature used in human activities that are replenished by natural processes on shorter cycles.
Non-renewable resources: Natural elements exploited by humanity that exist in fixed amounts and cannot be renewed on a human time scale.
Natural resources can be endless, such as direct solar, wind, and tides, or exhaustible, such as coal, oil, rocks, minerals, water, domestic animals, and cultivated plants.
Impact of Resource Consumption
The depletion and overexploitation of resources lead to pollution and waste production.
Major Current Environmental Problems
- Pollution: The alteration of the physical, chemical, or biological environment.
- Desertification: The process of intensification or expansion of desert-like conditions in areas that were previously fertile.
- Decrease of aquifers: Occurs when the water table drops within an aquifer.
- Extinction of species: Occurs when a species is lost forever from the biosphere.
Geological Processes
Geological processes are the various ways in which external agents model the Earth's surface:
- Weathering: Rocks break down and disintegrate into smaller components such as clays and sands.
- Erosion: The process of wearing down materials by the action of rain, rivers, and wind.
- Sedimentation: The process of transporting and depositing materials.
Types of Rocks
- Igneous or magmatic rocks: Originate from the solidification of magma.
- Sedimentary rocks: Formed from other rocks, shallow living organisms, or deposits on the surface of the crust.
- Metamorphic rocks: Originate from other rocks that have been transformed.
The Geologic Cycle
Geological agents break rock types and move fragments to lower areas of the relief, forming sediment that accumulates to create sedimentary rocks. When these rocks are buried deep in the Earth's crust, high pressure and temperature transform them into metamorphic rocks. These rocks may eventually melt into magma, which cools to create magmatic rocks.
Formation of Sedimentary Rocks
External agents tear materials from upland areas and transport them to lowlands. Sedimentary basins accumulate large thicknesses of sediment, forming layers called strata. Pressure from upper layers on the lower ones creates the conditions required to transform these sediments into sedimentary rocks. They constitute 70% of the land area and form a significant part of the landscape.
Sedimentary Rock Types
- Detrital: Consisting of fragments of other rocks (clay, gravel, etc.).
- Chemical or biological precipitation: Evaporitic rocks, rock salt, etc.
- Organic origin: Charcoal, etc.
Coal
Coal is used in the steel industry and power plants to generate electricity. Mining is dangerous, and the extraction of large quantities generates significant environmental impacts. Its consumption is a major source of air pollution, contributing to the greenhouse effect and acid rain.