M2 Subtopic 2 Flashcards
External processes that occur on or near the Earth’s surface. They are driven by external forces such as solar energy and gravity
Exogenic Processes
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
The process by which rocks and minerals break down into smaller particles
through physical, chemical, and biological means
Weathering
Three Types of Weathering
Physical (Mechanical) Weathering
Chemical Weathering
Biological Weathering
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 crack
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
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. For example, feldspar in granite reacts with water to form clay minerals
Hydrolysis
Minerals react with oxygen, often leading to rust formation. Common in rocks containing iron.
Oxidation
Carbon dioxide dissolved in water forms carbonic acid, which reacts with minerals like limestone, causing them to dissolve
Carbonation
Minerals dissolved directly in water, such as halite (rock salt) dissolving in rainwater
Solution
Involves the breakdown of rocks by living organisms
Biological Weathering
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 Mosses
Burrowing animals and insects can physically break down rocks
Animal Activities
Importance of Weathering
Soil Formation
Landscape Shaping
Nutrient Cycling
The process by which natural forces move weathered rock and soil from one place to another
Erosion
Enumerate the Four Agents of Erosion.
Water Erosion
Wind Erosion
Glacial Erosion (Ice)
Gravitational Erosion
Types of Water Erosion
Hydraulic Action
Abrasion
Solution
Forms v-shaped valleys
Types of Wind Erosion
Deflation
Abrasion
Types of Glacial (Ice) Erosion
Plucking, Abrasion
Forms u-shaped valleys
Type of Gravitational Erosion
Mass Wasting
The geological process by which sediments, soil, and rocks are added to a landform or landmass.
This occurs when the forces carrying the sediments (such as water, wind, or ice) lose their energy and can no longer transport the material, causing it to settle and accumulate
Deposition
Process of Deposition
Decrease in Transporting Medium’s Energy
Sorting of Sediments
Deposition in Different Environments
Heavier and larger particles settle first, followed by progressively finer sediments
Graded Bedding
Layers of sediment are deposited at an angle to the horizontal, commonly found in environments like rivers and deserts
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
Results from the movement and melting of glaciers, forming moraines and outwash plains
Glacial Deposition
Happens in oceanic environments, forming features like continental shelves and abyssal plains
Marine Deposition
Formed by wind deposition in deserts and coastal areas, where sand accumulates in mounds or ridges
Sand Dunes
Accumulations of dirt and rocks that have been pushed along by a glacier. When the glacier retreats, it leaves these deposits behind. Example
Moraines
Fine, wind-blown sediments that accumulate and form extensive deposits, typically found in regions with glacial history
Loess Deposits
Formed by wave action depositing sand and gravel along shorelines.
Beaches and Coastal Features
Importance of Deposition
Landform Creation
Soil Fertility
Ecological Habitats
Human Settlement
also known as mass movement, refers to the downslope movement of rock, soil, and debris under the direct influence of gravity.
Mass Wasting
Types/Processes of Mass Wasting
Creep
Slide
Flow
Falls
slow, gradual, and almost imperceptible movement of soil and rock downslope
Creep
A sudden and rapid movement of a cohesive block of soil or rock along a defined plane of weakness.
Slide
Movements along a flat or planar surface, such as a bedding plane or fault
Translational Slide
Movement along a curved surface, causing the material to rotate backward.
Rotational Slide (Slump)
Movement of rock, soil, and debris mixed with water, behaving like a fluid.
Flow
Types of Flows
Earthflows, Mudflows, Debris Flows
Free-fall of rock or debris from a steep cliff or slope
Falls
Factors Influencing Mass Wasting
Slope Angle
Material Composition
Water Content
Vegetation
Human Activities
