Sedimentary Environments and Geological Processes

Petrogenetic sedimentary environments are located outside the Earth's crust. They occur at low temperature and pressure, but as depth increases, they reach the border of metamorphism.

Types of Sedimentation

Sedimentary environments such as rivers, glaciers, wind, and the sea operate where there is a loss of energy, causing matter to accumulate in lower basins. These accumulations form sediments through two main processes:

• Gravity sedimentation: Involves pieces of stone or solid detritus.
• Chemical precipitation: Results in chemical sediments. Bioclastic sediments occur when organisms affect the precipitation of these chemical substances.

Continental Sedimentary Environments

• Alluvial environment: Found in mountain torrents where sediments form alluvial fans.
• Open dunes: Wind-generated environments with very round sand particles.
• Salt plains (Sabkhas): Located in arid regions or endorheic basins.
• Glacial deposits: Known as moraines, these sediments vary greatly in size and variety.
• Marshes: Characterized by vegetation, water, slow-moving organic matter, and fine materials concentrated in these areas.
• Lakes: Lake sedimentation is classified into three types: detrital, chemical, and intermediate.
• Rivers: Sediments are transported and classified by size; the longer the transport, the more circular they become.
• Floodplains: Sedimentation occurs during floods when the region is filled with water.

Marine Sedimentary Environments

• Reefs: Located on shallow sea bottoms with very clean water, where waves shake the area in warm climates.
• Continental shelf: Detrital sediments are sorted by size at the edge of the sea. Chemical carbonate sediments are also found here.
• Continental slopes: The transition area where materials reach the deep sea bottom; these are often very fine.
• Abyssal plain: Features minimal pelagic sedimentation from the dead skeletons of floating microorganisms.
• Beaches: Characterized by worked, small, and round sediments, along with remains of marine organisms.

Classification of Soil Types

Zonal Soils

• Permafrost: Soils that remain frozen throughout the year.
• Podzols: Soils found in cold and rainy climates.
• Chernozems: Soils typical of continental climates.
• Mediterranean Red Soils: Found in regions with hot summers and wet winters.
• Laterites and Bauxite: Found in tropical and humid equatorial regions.

Azonal Soils

• Gley Soils: Found in swampy areas.
• Alluvial Soils: Recently accumulated material in river areas.