Earth's Geodynamics: Internal Processes, External Agents, and the Rock Cycle

Internal Geological Processes and Earth's Relief

Internal geological processes are responsible for the formation of Earth's relief. Plate tectonics explains the deformation of the crust and the formation of large mountain chains. Conversely, external agents produce geological weathering of rocks, destroy topography, and shape the landscape.

Understanding Diagenesis

Diagenesis includes all mechanical and chemical processes affecting a sedimentary deposit after its formation.

The Rock Cycle: Interaction of Earth Processes

The rock cycle represents the interaction of the Earth's internal and external processes.

The cycle involves three main rock types:

• Sediments, when compacted, cemented, and sometimes recrystallized, form sedimentary rocks.
• Rocks subjected to high temperatures and pressures form metamorphic rocks.
• Rocks formed from the cooling and solidification of magma are magmatic (or igneous) rocks.

Sediments and Rock Transformation

Sediments are materials that are transported and deposited after sedimentation in a specific location. Sedimentary rocks are formed during the rock cycle.

Rocks are found in the depths of the Earth. Sedimentary rocks turn into metamorphic rock because they support large temperatures and high pressure. This rock also forms lava or magma, which, when mixed with minerals and other substances and coming into contact with water or the atmosphere, forms igneous rock or magma.

External Geological Processes (Geodynamics)

External geodynamics concerns the dynamic evolution of the planet's surface. The atmosphere, wind, sea, rain, rivers, ice, and living beings are the agents that produce external geological phenomena of altered rocks, known as external geological processes. These processes include:

• Weathering: The alteration of rocks by exposure to atmospheric agents and living organisms.
• Erosion: The alteration and fragmentation of rocks and minerals on the Earth's surface by geological agents.
• Transport: The displacement of fragments to different locations from their origin.
• Sedimentation: The deposit of eroded and transported material by geological agents in the lower areas of the planet or sedimentary basins. These basins may be continental or oceanic.