Geology is the science that studies the structure, composition, and transformation processes of the Earth, which is divided into three main layers: the crust, mantle, and core. These layers interact through mechanisms like mantle convection, which drives plate tectonics. This explains the movement of continents, the formation of mountains and oceans, as well as phenomena such as earthquakes and volcanism.
It classifies rocks into three types: igneous (formed from solidified magma), sedimentary (formed by the compaction of particles transported by water, wind, or ice), and metamorphic (transformed by pressure and temperature). Forces of erosion, transport, and deposition shape the Earth’s landscapes, forming features like valleys, dunes, and deltas.
Geology is based on the geological time scale, dividing Earth's 4.6-billion-year history, and relies on the dating of rocks and fossils to understand the evolution of climates, ecosystems, and landforms. It plays a crucial role in the exploration of natural resources (minerals, hydrocarbons, groundwater), the management of natural hazards (earthquakes, landslides, volcanic eruptions), and the study of climate change through geological records. Thus, geology is essential for understanding the Earth and addressing environmental and societal challenges.
- Enseignant: LEILA BENNACER