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    Faulting and Folding Concept Sheet

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    Lili Montefalco
    1) Tectonic plate movement results in folding and faulting of the Earth's crust. 2) Folding occurs when horizontal compression causes rock layers to bend, such as during continent-continent collisions. Common fold types include anticlines and synclines. 3) Faulting occurs when rock layers fracture and one side moves relative to the other along a fault plane. Fault types include normal, reverse, strike-slip, and transform faults depending on the direction of movement.

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    Faulting and Folding Concept Sheet

    Uploaded by

    Lili Montefalco
    16 views2 pages
    1) Tectonic plate movement results in folding and faulting of the Earth's crust. 2) Folding occurs when horizontal compression causes rock layers to bend, such as during continent-continent collisions. Common fold types include anticlines and synclines. 3) Faulting occurs when rock layers fracture and one side moves relative to the other along a fault plane. Fault types include normal, reverse, strike-slip, and transform faults depending on the direction of movement.

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    1) Tectonic plate movement results in folding and faulting of the Earth's crust. 2) Folding occurs when horizontal compression causes rock layers to bend, such as during continent-continent collisions. Common fold types include anticlines and synclines. 3) Faulting occurs when rock layers fracture and one side moves relative to the other along a fault plane. Fault types include normal, reverse, strike-slip, and transform faults depending on the direction of movement.

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    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    16 views2 pages

    Faulting and Folding Concept Sheet

    Uploaded by

    Lili Montefalco
    1) Tectonic plate movement results in folding and faulting of the Earth's crust. 2) Folding occurs when horizontal compression causes rock layers to bend, such as during continent-continent collisions. Common fold types include anticlines and synclines. 3) Faulting occurs when rock layers fracture and one side moves relative to the other along a fault plane. Fault types include normal, reverse, strike-slip, and transform faults depending on the direction of movement.

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    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
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    TECTONIC PROCESSES: FAULTING AND FOLDING

    Concepts/ Terms to Remember:


     main principles given by the Theory of Plate Tectonics
    - The Earth’s outermost rigid layer (lithosphere)is broken into discrete plates each moving (more or
    less) as a unit.
    - Driven by mantle convection, the lithospheric plates ride over the soft, ductile asthenosphere.
    - Different types of relative motion and different types of lithosphere at plate boundaries create a
    distinctive set of geologic features.
     Concepts to remember about the Lithospheric Plate
    - The lithosphere consists of the crust and the uppermost mantle. The average thickness of
    continental lithosphere is about 150km while the average thickness of old oceanic lithosphere is
    100 km
    - The Composition of both continental and oceanic crusts affect their respective densities.
    - The lithosphere floats on a soft, plastic layer called asthenosphere.
    - Most plates contain both oceanic and continental crust; a few contain only oceanic crust.
    - A plate is not the same as a continent.
     The Wilson Cycle
    In 1966, J. Tuzo Wilson proposed a cycle that includes continental break-up, drifting, collision and
    re-assembly of the continent. This tells us that Plate Tectonics is cyclic.
     The ff. are the main phases of the Wilson Cycle:
    - Rifting within the supercontinent leads to the opening of new ocean basin and formation of
    oceanic crust.
    - The passive margin cools and sinks, and sediment accumulates along the edge.
    - Convergence begins, initiating subduction and eventual ocean closure.
    - Continent-continent collision forms the next supercontinent.
     Forces that drive the movement of the Plates
    - Convection in the mantle (the sinking of denser material and rising of hot, less dense material)
    appears to drive plate motion.
    - Gravity-driven mechanisms such as slab-pull and ridge-push are thought to be important in driving
    plate motion. Slab-pull develops when cold, dense subducting slab of lithosphere pulls along the
    rest of the plate behind it. Ridge-push develops as gravity pushes the lithosphere off the mid-ocean
    ridges and toward the subduction trenches.
     Tectonic Forces results to tectonic processes that can be categorized as either Folding or Faulting.
     Folding -happens when rocks are pushed toward each other from opposite sides resulting to rock layers
    bend into folds. They are produced by horizontal compressive stresses such as continent – continent
    collision or collision of any convergent plate boundary. It is a known feature of ductile deformation.
     Common Types of Folds:
    - Anticline – upward arching fold
    - Syncline – downward arching fold
     Limbs – sides of a fold
     Dome -circular or elliptical anticline, limbs dip away in all directions
     Basin – circular or elliptical syncline, limbs dip towards the center
     Faulting – is the fracturing and displacement of brittle rock strata along a fault plane. Faults are
    fractures in the crust along which the displacement has occurred. Faults are features of brittle
    deformation.
     Types of faults based on the relative movement of the blocks on either side of the fault:
    - Dip- slip fault – happens when the movement of the 2 blocks is vertical. Examples include normal
    and reverse faults. In normal fault, hanging wall block moves down relative to the footwall block. In
    reverse fault, hanging wall moves up relative to the footwall block.
    - Strike slip fault – happens when the displacement is horizontal and parallel. It can be described
    based on their direction or motion. Sinistral fault is a strike slip fault that moves in a left lateral
    motion while Dextral fault is a strike slip fault that moves in the right lateral motion. A transform
    fault is a special variety of strike-slip fault that accommodates relative horizontal slip between other
    tectonic elements, such as oceanic crustal plates.

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