Soil production on a retreating escarpment in southeastern Australia

Research Article| September 01, 2000 Soil production on a retreating escarpment in southeastern Australia Arjun M. Heimsath; Arjun M. Heimsath 1Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA Search for other works by this author on: GSW Google Scholar John Chappell; John Chappell 2Research School of Earth Sciences, Australian National University, Canberra ACT 0200, Australia Search for other works by this author on: GSW Google Scholar William E. Dietrich; William E. Dietrich 3Department of Geology and Geophysics, University of California, Berkeley, California 94720, USA Search for other works by this author on: GSW Google Scholar Kunihiko Nishiizumi; Kunihiko Nishiizumi 4Space Sciences Laboratory, University of California, Berkeley, California 94720, USA Search for other works by this author on: GSW Google Scholar Robert C. Finkel Robert C. Finkel 5Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, California 9455, USA Search for other works by this author on: GSW Google Scholar Geology (2000) 28 (9): 787–790. https://doi.org/10.1130/0091-7613(2000)28<787:SPOARE>2.0.CO;2 Article history received: 24 Mar 2000 rev-recd: 09 Jun 2000 accepted: 14 Jun 2000 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Arjun M. Heimsath, John Chappell, William E. Dietrich, Kunihiko Nishiizumi, Robert C. Finkel; Soil production on a retreating escarpment in southeastern Australia. Geology 2000;; 28 (9): 787–790. doi: https://doi.org/10.1130/0091-7613(2000)28<787:SPOARE>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The functional dependence of bedrock conversion to soil on the overlying soil depth (the soil production function) has been widely recognized as essential to understanding landscape evolution, but was quantified only recently. Here we report soil production rates for the first time at the base of a retreating escarpment, on the soil-mantled hilly slopes in the upper Bega Valley, southeastern Australia. Concentrations of 10Be and 26Al in bedrock from the base of the soil column show that soil production rates decline exponentially with increasing soil depth. These data define a soil production function with a maximum soil production rate of 53 m/m.y. under no soil mantle and a minimum of 7 m/m.y. under 100 cm of soil, thus constraining landscape evolution rates subsequent to escarpment retreat. The form of this function is supported by an inverse linear relationship between topographic curvature and soil depth that also suggests that simple creep does not adequately characterize the hillslope processes. Spatial variation of soil production shows a landscape out of dynamic equilibrium, possibly in response to the propagation of the escarpment through the field area within the past few million years. In addition, we present a method that tests the assumption of locally constant soil depth and lowering rates using concentrations of 10Be and 26Al on the surfaces of emergent tors. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.