1. Production rate calibration for cosmogenic 10Be in pyroxene by applying a rapid fusion method to 10Be-saturated samples from the Transantarctic Mountains, Antarctica.
- Author
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Bergelin, Marie, Balco, Greg, Corbett, Lee B., and Bierman, Paul R.
- Subjects
PYROXENE ,COSMOGENIC nuclides ,CALIBRATION ,DIABASE ,SAMPLING methods ,OCHRATOXINS ,BERYLLIUM - Abstract
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
10 Be in pyroxene and constraints on the production rate which provide new opportunities for measurements of multi-nuclide systems, such as10 Be/³He, in pyroxene-bearing samples. We extracted and measured cosmogenic10 Be in pyroxene from two sets of Ferrar Dolerite samples collected from the Transantarctic Mountains in Antarctica. One set of samples has10 Be concentrations close to saturation which allows for the production rate calibration of10 Be in pyroxene by assuming production-erosion 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 measured10 Be concentrations in the near-saturation sample set we find the production rate of10 Be in pyroxene to be 3.74 +/- 0.10 atoms g-1 yr-1 and is consistent with10 Be/³He paired nuclide ratios from samples assumed to have simple exposure. Given the high10 Be concentration measured in this sample set, a sample mass of ~0.5 g of pyroxene is sufficient for the extraction of cosmogenic10 Be from pyroxene using a rapid fusion method. However, for the set of samples having low10 Be concentrations, measured concentrations were higher than expected. We attribute spuriously high10 Be concentration to potential failure in removing all meteoric10 Be and/or a highly variable and poorly quantified measurement background. [ABSTRACT FROM AUTHOR]- Published
- 2024
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