『Abstract
　Interpretations of regolith and soil thickness in the context of landscape evolution are typically based on the notion that thickness is controlled by the interaction of weathering rates and erosion and tuned to topography. On sideslopes of the Ouachita Mountains, Arkansas, however, there is a high degree of local spatial variability that is largely unrelated to topography. This indicates nonequilibrium in the sense that there is no evidence of a balance between rates of weathering and removal, as is postulated in some conceptual models in geomorphology and pedology. Johnson's soil thickness model is applied as an alternative to interpret local variations in regolith thickness. At the study sites, regolith thickness is not generally related to slope, curvature, elevation, or pedogenic development in the solum. This indicates that variability in thickness is related chiefly to processes and controls acting in the lower regolith, below the solum. The primary controls of variability are local lithological variation, variable structural resistance associated with fractures and bedding planes in strongly tilted Paleozoic sedimentary parent material, and point-centered pedological influences of trees. A steady state regolith may be relatively rare. Results of this study suggest that a equilibrium regolith thickness is most likely in uniform lithology with a high degree of lithologic purity, less likely i interbedded sedimentary rocks, and more unlikely still if the latter are titled and fractured. Equilibrium thickness would also be more likely where the effects of bioturbation are more areally uniform (as opposed to the point-centered effects of individual trees) and where the biomantle is above the weathering front.』

Introduction
Theory
　Weathering, erosion, and soil production
　Soil thickness model
Assessing thickness processes
Study area
Methods
　Sample design and data collection
　Data analysis
Results
　Regolith thickness
　Topographic relationships
　Lithology
　Pedogenic development
　Bioturbation
Discussion and interpretations
Conclusions
Acknowledgments
References cited