Production Rate Calibration for Cosmogenic 10be in Pyroxene by Applying a Rapid Fusion Method to 10Be-Saturated Samples from the Transantarctic Mountains, Antarctica

Measurements of multiple cosmogenic nuclides in a single sample are valuable for various applications of cosmogenic nuclide exposure dating and allow for correcting exposure ages for surface weathering and erosion and establishing exposure-burial history. Here we provide advances in the measurement of cosmogenic Be-10 in pyroxene and constraints on the production rate that provide new opportunities for measurements of multi-nuclide systems, such as , in pyroxene-bearing samples. We extracted and measured cosmogenic Be-10 in pyroxene from two sets of Ferrar Dolerite samples collected from the Transantarctic Mountains in Antarctica. One set of samples has Be-10 concentrations close to saturation, which allows for the production rate calibration of Be-10 in pyroxene by assuming production-decay equilibrium. The other set of samples, which has a more recent exposure history, is used to determine if a rapid fusion method can be successfully applied to samples with Holocene to Last Glacial Maximum exposure ages. From measured Be-10 concentrations in the near-saturation sample set we find the production rate of Be-10 in pyroxene to be 3.74 +/- 0.10 atoms g(-1) yr(-1), which is consistent with paired nuclide ratios from samples assumed to have simple exposure. Given the high Be-10 concentration measured in this sample set, a sample mass of similar to 0.5 g of pyroxene is sufficient for the extraction of cosmogenic Be-10 from pyroxene using a rapid fusion method. However, for the set of samples that have low Be-10 concentrations, measured concentrations were higher than expected. We attribute spuriously high Be-10 concentrations to failure in removing all meteoric Be-10 and/or a highly variable and poorly quantified procedural blank background correction.