Landscapes, Erosion, and Sedimentation: Processes and Environments

Landscapes, Erosion, and Sedimentation

Landscape: A portion of land characterized by biotic, anthropogenic, and atmospheric elements.

Erosion: The removal of materials by geological agents, resulting in wearing and modeling of the land.

Transportation: The movement of materials by geological agents.

Sedimentation: The accumulation of material in depressed areas of the surface (sedimentary basins).

Physical Weathering

Rupture of rocks due to tensions arising from different processes:

• Gelifraction: The action of water expanding when it freezes, causing cracks within the rock.
• Thermoclasty: Rupture of rocks exposed to sunlight.
• Decompression: The expansion and cleavage that occurs in rocks formed at depth.

Chemical Weathering

Disintegration of rocks due to chemical alteration of their minerals:

• Oxidation: Oxygen reacts with some minerals, forming oxides.
• Dissolution: Minerals that are soluble in water dissolve.
• Carbonation: The reaction when water carrying dissolved CO2 comes into contact with minerals, making them soluble or easily disintegrated.
• Hydrolysis: The alteration of minerals reacting with H+ and OH- ions in water.

Biological Weathering

Rupture mechanics and chemical alteration of rocks due to living organisms.

Sediment Transport

Characterized by energy, selection, and maturation.

Sedimentary Basins

Areas where sediments accumulate and sedimentary rocks are formed.

Sedimentary Environments

• Continental: River, stream, ice.
• Marine: Coral reefs, marine basins, continental shelves.
• Transition: Beach.

River Valleys

Form terraces and meanders.

Torrents

Wild water flowing through a non-fixed course (brook, ravines, wadi).

Wind Erosion

• Deflation: The wind sweeps away smaller sediments.
• Abrasion: Wind carrying sand collides with rocks, distorting them into mushroom shapes (most effective in deserts and coasts).

Reg/Erg: Stone/sand dunes.

Glaciers

Ice accumulating from snow in polar and high mountain areas (moraines). Progressing more rapidly through the center than the edges due to friction.

Karst Modeling

Surface and groundwater capable of dissolving limestone.

Exokarstic Features

(Galleries, passages, sinkholes)

Endokarstic Features

(Caves and tunnels, shafts, stalagmites, stalactites, columns)