• journal_title：Geology
• Contributor：Allan R. Bacon ; Daniel deB. Richter ; Paul R. Bierman ; Dylan H. Rood
• Publisher：Geological Society of America
• Date：2012-
• Format：text/html
• Language：en
• Identifier：10.1130/G33449.1
• journal_abbrev：Geology
• issn：0091-7613
• volume：40
• issue：9
• firstpage：847
• section：Articles

We couple meteoric ¹⁰Be measurements with mass balance analysis of ⁹Be to estimate the soil residence time (SRT) of a biogeomorphically stable Ultisol in the Southern Piedmont physiographic region of the southeastern United States. We estimate SRT after correcting the meteoric ¹⁰Be inventory to account for observed ⁹Be losses, which indicate that more than half of the ⁹Be weathered from primary minerals has been leached from the upper 18.3 m of the Ultisol. Our estimates of minimum SRT range between 1.3–1.4 Ma and between 2.6–3.1 Ma under high and low (2.0 and 1.3 × 10⁶ atoms cm⁻² yr⁻¹, respectively), estimates of ¹⁰Be delivery. Denudation rates of the physiographic region corroborate our estimates. We redefine pedogenic time constraints in the Southern Piedmont, and demonstrate that the assumption of complete meteoric ¹⁰Be retention in acidic soil systems cannot always be made; the latter has far-reaching consequences for soil, sediment, river, and ocean research using meteoric ¹⁰Be.