Endogenic Processes PDF

Endogenic Processes  What is endogenic process? *Geological processes associate d with energy originating in th e interior of the solid earth. *It is associated with energy originating in the interior of the solid earth.  Magmatism Deformation Endogenic Volcanism...

Endogenic Processes  What is endogenic process? *Geological processes associate d with energy originating in th e interior of the solid earth. *It is associated with energy originating in the interior of the solid earth.  Magmatism Deformation Endogenic Volcanism Processes Metamorphism  3 Main Sources of heat on Earth 1. Heat from the accretion of Earth during its formation. 2. Frictional heating, caused by the sinking of core materials to the center of the planet. 3. Heat from the decay of radioactive elements. Magmatism  Magmatism Molten rocks that are found beneath Earth’s surface is called magma. When magma emerges at the surface it is called lava.  Magma can be generated in several ways…. 1. Decompression Melting happens when temperature stays the same but the pressure decreases occurs at divergent boundaries, where tectonic plates separate 2. Flux Melting melting triggers when volatiles or gaseous substances are added into the hot solid rocks. convergent margins 3. Heat transfer melting melting of surrounding rocks caused by very hot magma bringing in additional heat. occurs in ridges, rift valleys, hotspots and subduction zone 4. Partial melting rocks begins to melt but only certain minerals are melting. Volcanism  Volcanoes are visible manifestation of the process of rock formation  Mt. Mayon ( Stratovolcano/ Composite) Cinder cone Volcano  Two Types of Eruption 1. Effusive eruption dominated by the flow of lava and formation of lakes and fountains 2. Explosive eruption ejects ash and larger fragments of broken pyroclastic materials Metamorphism The process when a rock changes its form into new one without undergoing melting or disintegration is called metamorphism.  Metamorphism processes…. 1. Recrystallization changes in shape and size of minerals w/o changing its density. 2. Phase change transformation of one mineral to another mineral 3. Neocrystallization growth of new minerals that’s differs from the old rocks. 4. Pressure solution dissolution of mineral grains when rock is squeezed dominantly in one direction at low temperature and pressure and presence of water. 5. Plastic deformation minerals become flattened or elongated w/o changing the composition  What causes metamorphism? Heat Pressure Hydrothermal solution ▪ Hot water-based solutions escaping from the mass of Deformation  Tectonic forces operating inside the Earth causes rocks to undergo deformation. Stress causes rocks to deform.  *Kinds of Stress 1. Tensional Stress occurs when the dominant force is directed away from each other. 2. Compressional Stress formed when dominant force is directed towards each other. 3. Shear Stress develops when the two dominant force are directed towards each other but not along same axis. The resulting change in the rocks due to the different types of stress is called strain.  Three Stages of Deformation 1. Elastic Deformation (1st stage) Reversible strain 2. Ductile Deformation (2nd stage) Irreversible strain 3. Permanent Stage (last Stage)  STRUCTURES PRODUCED BY DEFORMATION  Joints Natural cracks in the rocks produced by brittle deformation  Faults Like joints, faults are also planar structures resulting from brittle deformation but there is sliding between the rocks.  Folds Folds are produced by deformation of ductile materials. Folds are contortions of rock layers forming wave-like curves.