Calibrating a long-term meteoric Be-10 accumulation rate in soil

Using 13 samples collected from a 4.1 meter profile in a well‐dated and stable New Zealand fluvial terrace, we present the first long‐term accumulation rate for meteoric 10Be in soil (1.68 to 1.72 × 106 at/(cm2 ·yr)) integrated over the past ∼18 ka. Site‐specific accumulation data, such as these, are prerequisite to the application of meteoric 10Be in surface process studies. Our data begin the process of calibrating long‐term meteoric 10Be delivery rates across latitude and precipitation gradients. Our integrated rate is lower than contemporary meteoric 10Be fluxes measured in New Zealand rainfall, suggesting that long‐ term average precipitation, dust flux, or both, at this site were less than modern values. With accurately calibrated long‐term delivery rates, such as this, meteoric 10Be will be a powerful tool for studying rates of landscape change in environments where other cosmogenic nuclides, such as in situ 10Be, cannot be used.