Understanding Plate Tectonics: Pangea, Continental Drift, and Plate Boundaries
Understanding Plate Tectonics
The global theory of plate tectonics explains the cause of phenomena occurring in the geosphere, including mountain formation, volcanoes, and earthquakes.
Pangea and Panthalassa
Pangea was a supercontinent where all continents were united. The unique ocean surrounding it was called Panthalassa.
Theory of Continental Drift
Alfred Wegener developed the theory of continental drift based on cartographic, geographical, and paleontological data. This theory posits that continents
Read MoreAtmosphere: Composition, Structure, and Climate Dynamics
Atmospheric Composition
The atmosphere consists of major and minor constituents, including reagents and non-variable elements.
Structure and Function of the Atmosphere
The sun emits ultraviolet, visible, and infrared electromagnetic radiation (shortwave, visible, and longwave). Radiation from the center of the spectrum penetrates atmospheric layers most easily, primarily as visible light. Short wavelengths have high energy and penetrating power. Longer wavelengths are emitted by the Earth and used
Read MoreConstruction Materials and Their Properties
Construction Materials
Construction is a material-intensive activity consuming vast quantities of resources like glass, metal, and PVC. Concrete is a preferred choice for building and infrastructure projects. It’s a composite of inert materials (sand and gravel) and a binder, cement. A chemical reaction with water (hydration) hardens the mixture, increasing its strength and rigidity. Additives can enhance color, setting time, and properties like waterproofing. Concrete’s initial pasty form allows
Read MoreSoil Colloids: Classification, Clay Minerals, and Formation
Soil Colloids: The Active Fraction of Soil
Colloids represent the active fraction of soil, playing a crucial role in soil properties and fertility.
Classification of Soil Colloids
Soil colloids can be broadly classified into two main categories:
- Organic: Humified fraction of organic matter.
- Inorganic: Silicate clays (phyllosilicates), Al and SiO2 gels (allophane and imogolite), and oxides and hydroxides of Fe and Al.
Nature of Clay Minerals
It’s important to differentiate between clay minerals and the
Tectonic Plates: Earth’s Dynamic Surface Explained
Understanding Tectonic Plates
A tectonic plate is one of the large, moving sections that form the Earth’s outermost layer, the lithosphere. These plates fit together like a patchwork puzzle and are shaped by the convection currents moving within the Earth’s upper mantle. They effectively float above the semi-fluid asthenosphere.
The Theory of Plate Tectonics
Plate tectonics is the scientific theory that explains the structure of the Earth’s surface. It states that the lithosphere is divided into several
Read MoreEarth’s Geochemical and Dynamic Units: A Comprehensive Analysis
Geochemical Units
Geochemical units are defined by the composition of the chemical materials that make them up.
Crust
The crust is the outermost layer of the Earth, extending from the surface to the Mohorovičić discontinuity. There are major differences in thickness and composition between continental and oceanic crust.
1) Continental Crust
The continental crust ranges from 25 to 70 km in thickness. It is very heterogeneous, consisting of dense quartz rocks, feldspars, and micas. The lower half is
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