10Be - 26Al exposure age calculator

For calculating an exposure age when erosion rate is known independently.

Multiple sample form -- Balco et al. (2009) Northeastern North America (NENA) calibration data set

Uses version 2.2 code. October, 2013.

Written by Greg Balco, balcs@u.washington.edu

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Be-10 calibration data from:
Balco, G., Briner, J., Finkel, R.C., Rayburn, J.A., Ridge, J.C., Schaefer, J.M., 2009, Regional beryllium-10 production rate calibration for northeastern North America. Quaternary Geochronology 4, pp. 93-107.

Calibration data: Text file

Small differences between reference production rates inferred from these data in the table below and in the source paper are the results of rounding errors and differences in the code used to do the calibration. For consistency, the reference production rates in the table below are calculated using the same code used to compute exposure ages.

Balco et al. only measured Al-26 concentrations in a few of the samples, yielding a not-particularly-precise production rate calibration for Al-26. Thus, reference production rates for Al-26 in the table below are calculated from those for Be-10 using (P26 / P10) = 6.75. This is consistent with the actual measurements; see paper for details.

Scaling scheme Reference Be-10 Percentage Reduced Reference Al-26
for spallation production rate (atoms/g/yr) uncertainty chi-squared production rate (atoms/g/yr)


Sample data entry:

Enter data block here.

Note change in Version 2.2:

Production rates and decay constants have been updated in this version to reflect the Be-10 restandardization and half-life revision in Nishiizumi et al., 2007. Thus, you must now specify the standard to which your Be-10 and Al-26 measurements have been normalized. This means that two input fields, the Be-10 and Al-26 standard names, have been added. You'll need to add two columns to your spreadsheets before cutting and pasting data. Refer to the new example spreadsheet here. For a list of currently available standards, see this page.

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