Longer-term and contemporary denudation rates, and the role of extreme events along a passive margin, Australia

Long-term evolution of denudational escarpments in southeastern Brazil

“…Long-term denudation rates of escarpments depend on geological structures, tectonics, climate and time (e.g., Summerfield, 1991;Riebe et al, 2000;Matmon et al, 2003;Goudie, 2004;Huggett, 2007). Several methods are commonly applied to evaluate the rates of the processes controlling the short-and long-term evolution of escarpments, including thermochronology (e.g., Cockburn et al, 2000;Persano et al, 2002;Hackspacher et al, 2004;Balestrieri et al, 2005;Gunnell et al, 2007;Hiruma et al, 2010) and measurement of cosmogenic nuclide concentrations (e.g., Fleming et al, 1999;van der Wateren and Dunai, 2001;Heimsath et al, 2006;Humphreys et al, 2006;Burke et al, 2009). Correlation to geomorphic features of escarpments is also used as a method to evaluate escarpment evolution (e.g., Matmon et al, 2002;Moore and Blenkinsop, 2006;Oliveira and Queiroz Neto, 2007;Prince et al, 2011).…”

“…Cosmogenic nuclide concentrations are widely applied in studies that focus on the understanding of the denudation of escarpments all over the world by measuring denudation rates from fluvial sediments, soil profiles and rock outcrops. This method is applied to study several escarpments, e.g., the Drakensberg escarpment in southeast Africa (Fleming et al, 1999;Cockburn et al, 2000;van der Beek et al, 2002;Chardon et al, 2006;Moore and Blenkinsop, 2006;Beauvais et al, 2008), the Great Escarpment in southeast Australia (Seidl et al, 1996;Persano et al, 2002;Heimsath et al, 2006;Humphreys et al, 2006;Burke et al, 2009) and the Blue Ridge escarpment in eastern North America (e.g., Hancock and Kirwan, 2007;Sullivan et al, 2007). This sort of research largely focuses on the individual denudation of escarpments as retreat and downwearing and on the geomorphic control on their denudation rates (von Blanckenburg, 2005).…”