Resumen de Combining low temperature apatite thermochronology with cosmogenic isotope analysis in long-term landscape evolution studies
Roland W. Brown, Hermione A.P. Cockburn, B. Kohn, D.X. Belton, D. Fink, Michael A. Summerfield
Perhaps the most challenging aspect o f studying long-term landscape evolution is the need to measure and integrate the rates o f Earth surface processes that operate over vastly different spatial and temporal scales. In recent years major advances in our understanding o f how continental scale landscapes change over geological time scales have come from the realisation that thermochronologic data (such as apatite fission track and UTh/He analysis) can be used to estimate broad, long-term (= 10 yr) erosion rates. However, it is difficult to relate these broad estimates to specijic landscape forming processes (eg. escarpment retreat, valley incision or widening), or to actual landscape elements (eg. escarpment faces, ridges or discrete low reliefsurfaces) or even to similarly broad scale erosion rate estimates made over much shorter time scales (from river sediment and solute load data for example). It is here that cosmogenic isotope analysis can make an important contribution. By providing estimates ofthe pattern and variability o f erosion rates over the key intermeadiate spatial and temporal scales cosmogenic isotope data provide a means ofextrapolating the wealth o f information gleanedfrom short term process studies to the broader spatial and temporal information obtainedfrom low temperature apatite thermochronology.
