Geology

• Diastrophism 


  this pertains to the movement of all solid parts of the earth
•  Upward forces


  cause the local or widespread rising or uplift of the crust
• Downward forces


  cause the local or widespread sinking subsidence of the crust
• Sideward force


  cause the horizontal motion of the crust called thrust. Large masses of rocks slide and slip against each other into new positions
• Folding


  occurs when the crust crumples or wrinkles due to compressions or pushes from opposite directions. As the crust is crumpled, the rock strata become tilted.
• Faulting


  occurs when the rock masses of the crust are pulled apart forming cracks or fractures on the crust. The rock layers slide and slip against each other along the breaks.
• Continental Drift Theory

  proposed by Alfred Wegener, according to him 200 years ago, there was only a single super continent called Pangaea situated at the center of the equator. It broke up into pieces which slowly moved away from each other. The pieces formed the continents today.
•  Theory of Seafloor Spreading


   five years after Wegener discovery a brake or rift was found at the middle of the ridge running along its length where ballistic magma wells out to the surface. This ballistic magma solidified forming a new crust it pushes the old crust causing the ocean floor

  to spread
• Plate Tectonic Theory


   it proposed that the lithosphere is divided into six more plates. The plate may be composed of the continental crust on top of the oceanic crust alone. These plates are slowly, but nevertheless continually in motion.
• Spreading or divergent boundary


  an area where two plates move apart leaving a gap between them. The gap formed is immediately

  filled up with molten material that wells up from lower mantle.
• Colliding or convergent boundary


   an area where two plates move toward each other. As the plates collide, the leading edges of one plate is bent downward allowing it to slide beneath the other.
• Fracture or transform boundary


  this is the area where two plates move past each other, sliding scraping and deforming the edges of

  the continents.
• Volcanism


  the building up of landforms due to volcanic activities is rapid and process is dramatic
• Classification of volcanoes:

  Quiet


  exhibit non-explosive eruptions. But they

  discharge fluid lava and gases into the lower levels,

  destroying crops and burying everything in their path
• Classification of volcanoes:

  Explosive


  erupts violently
• Classification of volcanoes:

  Intermediate


  volcanoes are sometimes quiet, and

  sometimes explosive or a combination or both
• Earthquakes


  any movement or shaking of the ground
• Earthquakes

  Tectonic


  earthquake caused by the movement of tectonic plates

  or shifting of faults
• Earthquakes

  Volcanic


  earthquake caused by the movement of molten magma

  from deep under the earth’s crust up
• Epicentre


  point up on earth’s crust where an earthquake

  originates
• Kinds of Rocks:

  Igneous rocks


  heavy, unlayered, dark rocks formed by the cooling and hardening of molten materials called magma
• Igneous rocks

  Lava 


  magma that reaches earth’s surface
• Igneous rocks

  Igneous intrusive 


  formed from magma that did not reach surface of the earth. These are generally light-colored and have large crystals
• Igneous rocks

  Extrusive igneous rocks


  formed from lava that cooled down and solidified on the surface of the earth. Rapid cooling caused small crystals to form
• Kinds of Rocks:

  Sedimentary rocks


  formed by the accumulation and consolidation of mineral and particulate matter deposited by the action of water, wind, glacial ice.
• Sedimentary rocks

  Fragmental rocks


  are composed of mineral particles produced by mechanical disintegration, transported and deposited in layers. (shale to slate)
• Metamorphic rocks 


  the hardest kinds of rocks produced by the hardening of igneous and sedimentary rocks
• Weathering


  the process of breaking down rocks into smaller particles to become soil. A prerequisite of erosion
• Erosion


  the rock masses that crumble are further loosened and transported from one place to another by another natural process