Mechanisms of crustal subsidence  Sedimentary basins  Isostasy  Basins due to stretching  Basins due to cooling  Basins due to convergence  Basins

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Text of Mechanisms of crustal subsidence  Sedimentary basins  Isostasy  Basins due to stretching...

  • Mechanisms of crustal subsidenceSedimentary basinsIsostasyBasins due to stretching Basins due to coolingBasins due to convergenceBasins due to tearing of crust

  • Principles of isostasy

  • Hawaiin seamount chain with flexed lithospheric lows

  • Basins due to stretching

  • Mantle plumes associated with rifting not required, but do occur e.g. North Atlantic rifting and emplacement of Tertiary igneous province

  • Half-graben formation during rifting

  • Faults, lakes and volcanoes dominate the landscape

  • Lakes filling half-grabens with thinned lithosphere generating heating and volcanism

  • Basins due to thermal subsidence

  • Basins due to thermal subsidence after heating following rifting passive margins

  • Typical form of a passive margin

  • Passive margin accumulates thick sediment that drapes the continent/ocean transition.

    Subsidence is slow and exponentially declines as cooling of rifted lithosphere slows.

  • Basins due to convergence

  • Crustal depressions due to loading during subduction accretionary trench

  • Basins due to loading of continental lithosphere Foreland Basins

  • Basins due to tearing strike-slip basins(pull-apart)

  • San Andreas Fault

  • Basins due to tearing of crust strike-slip basins

  • SummarySedimentary Basin form by a number of meansLithosphere can stretch (Rift basins)Cool and subside (Passive margins)Be loaded and bend (accretionary trench on oceans Foreland basin on continents)Tear apart to form pull-apart or strike-slip basins.Isostasy is critical