Louis Brown J. Nathalie Valette-Silver Jeffrey Klein Roy Middleton M.J. Pavich 1985 <div id="15569263" class="article-section-wrapper js-article-section js-content-section " data-section-parent-id="0"><p>Samples from a residual weathering profile in the Virginia Piedmont have been analyzed for cosmogenic<span>&nbsp;</span>¹⁰Be. Concentrations are highest in clay-rich soil and decrease exponentially to a depth of about 15 m. Despite uncertainties about the processes by which<span>&nbsp;</span>¹⁰Be may be intercepted before entering the solum and eroded after incorporation, a minimum age may be calculated for the regolith. This calculation is based on the delivery rate of<span>&nbsp;</span>¹⁰Be and its decay rate and suggests that this residual profile developed during a period no shorter than 8 × 10⁵<span>&nbsp;</span>yr. The calculated minimum age may be within a factor of 2 of maximum-age estimates based on surface lowering by erosion and on the rate of rock weathering to saprolite. The vertical distribution of<span>&nbsp;</span>¹⁰Be in the profile could result from a steady-state balance of deposition, weathering, radioactive decay, and erosion.</p></div> application/pdf 10.1130/0091-7613(1985)13<39:BAOAQW>2.0.CO;2 en Geological Society of America 10Be analysis of a Quaternary weathering profile in the Virginia Piedmont article