Erosion cratons

This is in part because denudation rates are very low and because sea-level fluctuation may be important to the erosion process. Cratons seem to undergo major episodes of erosion following drops of sea level. When the level drops to a stable stand of several million years, much of the landscape is eroded down to the new level and an erosion surface or a planation surface forms. 

Transport and distribution of sediments derived from Andean erosion across the cratonic landscape of Brazil have caused development of an upstream to downstream trend in geomorphic and hydrologic character of the channel-floodplain system (Mertes et al. 1996). In upstream reaches, scroll bar topography on the floodplain tends to... 

An enduring question in the study of the Earth concerns the origin and stability of Archaean cratons (Jordan 1978 Bickle 1986 Helmstaedt Schulze 1989 Hoffman 1990 Abbott 1991). They drift around the globe with remarkable resistance to tectonic deformation and thermal erosion. A key to understanding the nature of these cra-... 

These studies have implications for the stability of cratons and diamond exploration. The steep gradients focus flow and adiabatic decompression melting along cratonic boundaries where exten-sional body forces arising from the density contrast between normal asthenosphere and hot plume material will be the largest, indirectly focusing tectonism. This in turn further shields the cratonic cores, although lateral erosion of... 

The second section contains papers modelling cratonic evolution and accretion. Sleep et al. present numerical models of cratonic roots in normal mantle flow and in the presence of plumes. Cratons may suffer lateral erosion rather thinning. Bleeker reviews the tectonic evolution of Archaean granite-greenstone terrains. Then, taking... 

The development of topography consisting of stacked erosion surfaces on many shields indicates that vast areas of cratons are undergoing a slow but sustained rise relative to sea level. The remnants of erosion surfaces are evidence of the former thickness of the cratons. It is interesting to speculate that this tendency to rise has held true for many shield areas... 

Cratons. Ancient crystalline terranes, forming extensive cratons and large tracts of continental interiors, are generally viewed as tectonically and isostatically stable, and resistant to internal deformation. A growing body of evidence however, based on reconnaissance apatite studies of different cratons and Precambrian blocks, has revealed discrete, regional episodes of Phanerozoic km-scale cmstal erosion of these ancient terrains (Crowley et al. 1986, 1991 Zeck et al. 1988, Brown et al. 1990, Noble et al. 1997, Spikings et al. 1997, Harman et al. 1998, Mitchell et al. 1998, Cederbom et al. 

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