1. Combining low temperature apatite thermochronology and cosmogenic isotope analysis in quantitative landscape evolution studies Roderick Brown, Hermione Cockburn, Barry Kohn, David Belton, David Fink, Andrew Gleadow and Michael Summerfield The University of Melbourne Australian Nuclear Science & Technology Organisation The University of Edinburgh

3. Conceptual landscape evolution models

5. Numerical landscape evolution models van der Beek et al. (2002)

6. Numerical landscape evolution models

8. Southern Africa

9. Drakensberg Escarpment

10. Landsat ETM+ 321RGB Image

11. Drakensberg Escarpment, Sani Pass

12. Sani Top Photograph by Alastair Fleming

13. Apatite Fission Track Age

14. Estimated Palaeogeothermal Gradients

16. Atlantic Margin, Namibia

17. Gamsberg Escarpment, ASTER VNIR Image

21. Gamsberg Plateau, ASTER VNIR Image

22. Gamsberg Escarpment Photograph by Hermione Cockburn

23. Gamsberg Escarpment Photograph by Hermione Cockburn

24. Gamsberg Plateau Transect

25. Gamsberg Escarpment Transect

26. South Eastern Australia

27. South Eastern Australia, 300m DEM

28. Brown Mountain Transect 50 km

29. Denudation since 110 Ma

30. Denudation since 65 Ma

31. Apatite U-Th/He Ages

32. Paired Apatite FT & He Ages

33. Apatite FT & U-Th/He Ages

34. Age of continental rifting

35. ANTARES Detector Array, ANSTO, Australia

37. Conclusions Measured denudation rates and chronologies for the Gamsberg, Drakensberg and Brown Mountain escarpments are incompatible with a steady, parallel retreat model Combined thermochronologic and cosmogenic datasets are capable of quantifying passive margin escarpment retreat rates A viable alternative model involves the establishment of an escarpment at a major inland drainage divide with moderate to low subsequent retreat rates