s2 Flashcards
(35 cards)
processes are external processes that occur on or near the Earth’s surface. They are driven by external forces such as solar energy and gravity
Exogenic Process
processes are internal processes that originate within the Earth. They are driven by internal forces such as heat from the Earth’s interior and gravitational energy
Endogenic Process
involves the breakdown of rocks and minerals into smaller pieces without changing their chemical composition.
Physical Weathering (Mechanical Weathering)
Water seeps into cracks, freezes, expands, and eventually breaks the rock apart. Common in cold climates.
Freeze-Thaw (Frost Wedging)
Rocks expand when heated and contract when cooled. Repeated temperature changes can cause the rock to crac
Thermal Expansion
Rocks and particles scrape against each other, causing them to wear
down. Common in windy areas and riverbeds.
Abrasion
Layers of rock peel off due to pressure release or thermal expansion.
Exfoliation
arbon dioxide dissolved in water forms carbonic acid, which reacts
with minerals like limestone, causing them to dissolve.
Carbonation
involves the chemical alteration of minerals within rocks, leading to their breakdown
Chemical Weathering
Water reacts with minerals to form new minerals and soluble salts.
Hydrolysis
Heavier and larger particles settle first, followed by progressively finer sediments.
Sorting of Sediments: Graded Bedding
Minerals react with oxygen, often leading to rust formation.
Common in rocks containing iron
Oxidation
Minerals dissolved directly in water, such as halite (rock salt)
dissolving in rainwater.
Solution
Roots grow into cracks in rocks, exerting pressure and causing
the rock to break apart.
Plant Roots
These organisms produce acids that chemically weather
the rock surface.
Lichens and Mosse
Involves the breakdown of rocks by living organisms
Biological Weathering
Deflation: Removal of loose particles from the ground.
Abrasion:
Windblown particles grind against surfaces, smoothing and shaping them.
Examples: Sand dunes, desert pavements, and loess deposits
Wind erosion
Erosion is the process by which natural forces move weathered rock and soil from
one place to another.
Erosion
Hydraulic Action: The force of moving water dislodges and transports particles.
Abrasion: Rocks and sediments carried by water wear away the riverbed and banks.
Solution: Minerals dissolve in water and are carried away.
Water Erosion
Movement of rock and soil downslope due to gravity.
Examples: Landslides, rockfalls, and soil creep
Mass Wasting
Layers of sediment are deposited at an angle to the horizontal, commonly found in
environments like rivers and deserts
Sorting of Sediments: Cross-Bedding
Occurs in river and stream environments, forming features
like deltas, alluvial fans, and floodplains.
Fluvial Deposition
Caused by the wind in the desert and coastal environments,
forming sand dunes and loess deposits.
Aeolian Deposition
Formed where a river meets a standing body of water such as sea or lake, causing sediments to be deposited as the river’s velocity decreases
Deltas