Components Of The Lithosphere

Topics: Plate tectonics, Earth, Lithosphere Pages: 13 (2881 words) Published: April 24, 2015

Components of the Lithosphere
-Rigid Outer Layer
-Crust and upper mantle
-tectonic plates
Theory of Plate Tectonics
-Theory that Earth's surface is composed of large, thick plates that move and change in size

-Combined hypotheses of continental drift and seafloor spreading, plus new observations using geophysics superconinents
Pangea: super continent

-Godwana: (Permian), southern super continent, south America, Australia, new guinea

Lavrasia: northern super continent
Types of Plate Boundaries


-Permineralization: petrified wood
-Minerals and cast: impression in material filled in by another -Carbonization and empression: when carbon film is lost
-Amber: harder resin of ancient trees
Divergent Boundary
-Tension creates rifting
-Creates new ocean basins
-Uplift due to hot, rising, less dense magma
-Shallow earthquakes
-Grabens= normal faulting
study of fossils
Transform Boundaries
-two plates slide past each other
-Offset along other types of plate boundaries
-Shear motion along faults
-May occur as a single fault, or groups of parallel faults
Convergent Boundaries
-two plates coming together
-One subducts and is damages
-Oceanic plate is older, colder, denser, gets subducted
-Characteristics depend on collision type
              -Ocean continent           
Ocean Ocean Convergence
-subduction causes a benioff zone
-creates a deep broad trench
-Accretionary Wedging: marine sediments are scraped off
-Partial melting of the asthenosphere(due to flux melting)
Magma forms an island arc
-Oceanic crust is first subducted until ocean closes
-Neither plate wants to subduct(least buoyant does)
-Forms Suture zone plate boundary(in middle)
-Crust is greatly thickened, creates a large mountain belt and shallow focus earthquakes -Continental collision, mountain belts, thrust faults, and detached subducting plates involved Ocean- Continent convergence

-Oceanic plate subducts below less dense cont. crust creating a benioff zone -magma forms and creates magmatic arcs of andesitic volcanoes -Inc. heat causes metamorphism
-Isostatic uplift of Cont. Crust
-Subsidence creates an inland basin
-***Same features as ocean-ocean except volcanoes are built on continental crust, and sometimes backarc thrust belts can form Benioff zone
Tilted zone of earthquakes associated with subduction zones
Ocean-Continent Convergence Continued
Volcanoes(magmatic arc): more silicic form addition of continental material, batholiths form at depth

-Backarc thrust belt: thrust faults form behind arc in response to convergence, cause stickiness between plates Thrust Fault

Internal Forces in the earth that drive plate tectonics/What causes Plate motion -Ridge Push: sliding of lithosphere away from ridge crest, GRAVITY DRIVEN FORCE THAT RESULTS FROM THE ELEVATED POSITION OF THE RIDGE  -Slab pull: Subducting cold, dense, oceanic lithosphere pulls the plate away from ridge crest, MAJOR DRIVING FORCE OF PLATE MOTION, mantle drag and friction resist subduction -Trench Suction: steep subduction can cause overlying plate to be pulled horizontally

Driving Forces of Plate Motion COnt.
-Mantle Convection is the most likely candidate, but it could be either the cause of effect of ridge push and slab pull

-Convection in the mantle enhances plate motion when the velocity of the asthenosphere exceeds that of the overlying plate Paleomagnetism
-Study of earth's magnetic pull over time
-reconstruct paleomagnetic poles form the alignment of magnetic minerals in rocks -When magnetite containing basaltic rocks cool below the curie point, the magnetite aligns toward the position of the north pole -The magnetite is frozen in position and indicates the position of the north pole at the time of solidification Magnetic reversal...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Health Components Essay
  • Component of Computer Essay
  • Components of Culture Essay
  • Components of Logistics Essay
  • Components of Fitness Essay
  • Fitness Components Essay
  • Isolating the Components of a Three Component Mixture Essay

Become a StudyMode Member

Sign Up - It's Free