4th Quater (endogenuc processes)

• Geothermal gradient is the increase in temperature with depth
• the main sources of Earth's Internal heat are the radioactive decay of isotopes, extraterrestrial impacts, and gravitational contraction of Earth
• Convection in the Earths interior is the motion of hot fluid from one place to another
• thermal budget is the amount of heat produced in the interior and released on the surface
• the primary heat released by the Earth's interior is heat from its primodial heat (heat from its early formation) and heat generated in the earths interior through radioactive decay
• the heat flow drives convection within the mantle and the core
• the thermal budget is computed through the study of energy emitted by the four major isotopes that produce heat namely Uranium-238, Thorium-232, and potassium-40
• the convection currents occur in the outer core because the outer core is a fluid layer
• thermal equilibrium - is more heat is generated than released, the mantle would heat up and discharge large amounts of heat in order to reach thermal equilibrium
• according to the nebular theory, the heat energy was produces when great amount of kinetic energy produced by moving objects, radioactive decay of unstable elements
• magmatism is the movement of magma
• the most abundant element in magma is oxygen
• magma originates within the mantle and the crust
• in decompression melting, hot materials move upward. hot materials move to an area of low pressure and hot mantle move through convection
• flux melting takes place in subduction zones
• the decompression melting happens in divergent boundaries
• flux melting happens when water is added to the rocks
• in flux melting, decreasing temperature cause the rocks to partially melt
• Granitic magma is more viscous than basaltiv magma
• basaltic magma contains low silica content while granitic magma contains high amounts of silica
• plutons and intrusive rocks are formed when magma chambers cool down
• magma is formed from partial melting because of the differences in minerals temperature and because of the differences in its mineral content
• volcanism is the process where magma rises on earths surface
• magma chamber is the reservoir where magma is stored and serves as the engine of a volcano'
• caldera is a part of a volcano that is considered as a very big depressionm
• the main factor for a volcanic eruption to occur is pressure
• effusive eruption can occur underwater and can form lava domes
• explosive eruption - as the magma rises, the pressure build up decreases and the pressure inside gas bubbles is greater than the surrounding magma
• composite or stratovolcanoes are usually large, conical, and have symmetric structures
• Shield volcanoes resemble a warrior's shield and have gentle slopes
• it has erupted for the past 10,000 years and its magma can be discharged by effusive eruption

  
• it is quite stable and may collapse, it is young in morphology, and it has no historical record of eruption

  
• james hutton proposed the theory of plutonism
• plutonism states that rocks were formed form heat driven processes
• crystallization is the formation of crystals
• plutonic is an intrusive and igneous rock
• examples of plutonic rocks

  • granite
  • peridotite
  • gabbro
• pluton is a solidified body of plutonic rocks that crystallized when the magma slowly cooled below the Earths surface. it is a solidified body of plutonic rocks and can be exposed through erosion
• plutonic rocks are formed in the interior of the Earth, while volcanic rocks form on the crust
• plutonic rock have croarser grains than volcanic rocks