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