Internal energy and landforms

Internal energy and landforms

1. Plate boundaries and their associated landforms

   • Divergent (Constructive) boundaries
     • Separation
     • New oceanic lithosphere creates
     • Ex: Mid-Atlantic RIdge
     • Ridges and contiental rifts
   • Convergent (Destructive) boundaries
     • Ex: Mariana Trench
     • Collision
     • Destroys oceanic lithosphere
     • Trenches, island arcs and mountains
   • Transform (Passive) boundaries
     • Ex: San Andreas Fault
     • Lateral displacement
     • Neither creates nor destroys oceanic lithosphere
     • Transform faults
   • Differences between island arc and volcanic archipelagos

2. Relief

   • Is defined as the interaction between internal and external geological processes

3. External geological processes

   • Weathering
     • Alters and breaks up rocks
   • Erosion
     • Geological agents erode land due to their own force
   • Transportation
     • The materials produced are transported towards depressed zones
   • Sedimentation
     • As the agents lose their power with transportation, materials are deposited creating different landforms

4. Internal geological processes

   • Types of deformations
   • Type of forces
   • Folds
     • Are created when rock deform, because of compression forces. Rocks do not break, but fold on different ways:
       • Classified into:
   • Faults
     • Are fractures in rocks where the separated of rocks have been displaced
       • Classified into:
     • Horsts and garbens
       • Occur within a fault zone where a series of normal faults are present

5. Magmatism and metamorphism

   • Metamorphism
     • Is a process (occurs only in solid state) where the distribution of the minerals in rocks changes because of different facts:
       • Contact metamorphism - ⇧ temperature, ⇩ pressure
       • Regional metamorphism - ⇧ temperature, ⇧ pressure
       • Dynamic metamorphisim - ⇩temperature, ⇧ pressure
   • Magmatisim
     • The internal temperature of the Earth increases with depth (geothermal gradient). Melting can occur due to:
       • Rise in temperature - produced by friction
       • Drop in pressure - reduces the melting point of rocks
       • Presence of liquids - reduces the melting point of rocks

6. The Wilson cycle

   • Proposed by John Tuzo Wilson
   • Its process:
   • It is based on the cycle of rfiting and reunited the continents

7. Orogenies

   • Are geological periods in the past during which mountains ranges were formed
   • Types of orogenies:

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