1. Mechanisms of crustal subsidence  Sedimentary basins  Isostasy  Basins due to stretching  Basins due to cooling  Basins due to convergence  Basins due to tearing of crust

3. Principles of isostasy

5. Hawaiin seamount chain with flexed lithospheric lows

7. Basins due to stretching

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

11. Half-graben formation during rifting

13. Faults, lakes and volcanoes dominate the landscape

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

15. Basins due to thermal subsidence

16. Basins due to thermal subsidence after heating following rifting– passive margins

17. Typical form of a passive margin

18. Passive margin accumulates thick sediment that drapes the continent/ocean transition. Subsidence is slow and exponentially declines as cooling of rifted lithosphere slows.

20. Basins due to convergence

21. Crustal depressions due to loading during subduction – accretionary trench

25. Basins due to loading of continental lithosphere – Foreland Basins

29. Basins due to tearing – strike-slip basins (pull-apart)

31. San Andreas Fault

32. Basins due to tearing of crust – strike-slip basins

33. Summary  Sedimentary Basin form by a number of means  Lithosphere 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