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GEOLOGIC PROCESSES ON EARTH

Geologic Processes on Earth

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Page 1: Geologic Processes on Earth

GEOLOGIC PROCESSES ON EARTH

Page 2: Geologic Processes on Earth

EXOGENOUS PROCESSES

• Occur on or near the surface of Earth

• Usually influenced or driven by gravity, water, wind and organisms

• In extreme cases, it can wipe out majority of the organisms inhabiting that area.

Page 3: Geologic Processes on Earth

WEATHERING

• The disintegration of rocks, soil and minerals together with other materials through contact with Earth’s subsystems

• Happens even without movement or transportation

Page 4: Geologic Processes on Earth

Physical Weathering

• Breakdown of rocks by mechanical forces concentrated along rock fractures

• Can occur due to changes in temperature and pressure

• Example : soil cracks because of extreme heat or drought

• In some cases, water, wind or ice may scrape rocks or soil

Page 5: Geologic Processes on Earth

Chemical Weathering

• Rocks break down by chemical reactions

• New or secondary minerals develop and sometimes replace the original properties of the minerals in the original rock or soil

• CONTRIBUTORS:

• OXIDATION – reaction of a substance with oxygen

• HYDROLYSIS – the chemical breakdown of a substance when combined with water

• ACID RAIN – may cause metals and stones to corrode or deteriorate and change their properties

Page 6: Geologic Processes on Earth

EROSION

• Process by which earth’s surface is worn away by wind, water, or ice

• Moves rock debris or soil from one place to another

• Takes place when there is rainfall, surface runoff, flowing rivers, seawater intrusion, flooding, freeing and thawing, hurricanes, wind, etc.

• Movement of land animals during migration or stampede

• Human activities: deforestation, overgrazing and mining

Page 7: Geologic Processes on Earth

MASS WASTING

• Movement of large masses of materials (rock debris, soil, mud) down a slope or a steep sided hill or mountain due to the pull of gravity

• Very destructive in areas with increased water flow.

• DEBRIS FLOW

• MUDFLOW

• SLUMP

Page 8: Geologic Processes on Earth

Mudflow

• Happens when combined soil and water flow down a slope

• Usually happens near rivers or streams where soil or sand is always moist or has been soaked in water for a long time.

Page 9: Geologic Processes on Earth

Debris flow

Happens when a large amount of sediments, usually rocks of various sizes, falls down the slope.

Does not need water to flow down

Page 10: Geologic Processes on Earth

Slump

• Slow movement of soil along a curved surface.

• In time, the area would look curved because of the depression formed by the sinking land

Page 11: Geologic Processes on Earth

SEDIMENTATION

• Accumulation of materials such as soil, rock fragments and soil particles settling on the ground.

• Usually occurs in streams or sea erosion

• Over time, the sediment load becomes thick and forms a new layer of ground

Page 12: Geologic Processes on Earth
Page 13: Geologic Processes on Earth

• If geologic processes seem to bring risk to human safety, where then is a safe place to live? Is there even any?

Page 14: Geologic Processes on Earth

ENDOGENOUS PROCESSES

• Takes place within or in the interior of Earth.

• The driving force is the thermal energy of the mantle.

• Responsible for earthquakes, development of continents, mountain building, volcanic activities, etc.

Page 15: Geologic Processes on Earth

MAGMATISM

• Magma is the original material that make up igneous rocks.

• Magmatism happens when a magma is generated and develops into igneous (magmatic) rocks

• The process can take place either under the surface or on the surface of Earth.

Page 16: Geologic Processes on Earth

VOLCANISM (PLUTONISM)

• Process that usually happens after the magma is formed.

• Magma tries to escape from the source through openings such as volcanoes or existing cracks on the ground.

• As soon as magma reaches the surface of the earth it is now called lava.

Page 17: Geologic Processes on Earth

METAMORPHISM

• Process of changing the materials that make up a rock.

• Chemical components and geologic characteristics of the rock changed due to heat and pressure that are increasing or decreasing.

• Note:

• Rocks changing due to weathering and sedimentation are not considered to have undergone metamorphism.

Page 18: Geologic Processes on Earth

• What drives the endogenous processes on Earth?

• Where does the force come from?

• Why is it called endogenous?