10Be - 26Al exposure age calculator


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

Multiple sample form. Version 2.3. June, 2016. Written by Greg Balco, balcs@bgc.org

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Erosion rates
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Use a test sample
for demonstration
purposes --

Enter data block here.See below for formatting instructions.


Note changes in Version 2.3:
Version 2.3 has updated muon interaction cross-sections and default Be-10 and Al-26 production rates. The latter are derived from the 'primary' calibration data set of Borchers and others (2016).
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It takes a few seconds to calculate each exposure age. If the timeout setting on your browser is too short, it will stop waiting for the page before the calculations are done. You can set the wait time to a longer value on some browsers. If that's not true of yours (Safari, for example), you will have to submit fewer samples at once.
Formatting instructions:
This form is designed to have text pasted into it from a text editor or an Excel spreadsheet. The formatting requirements are unforgiving, but easy to follow once you have a spreadsheet set up appropriately. An example spreadsheet is here. The rules are as follows:
  1. Enter plain ASCII text only.
  2. Each sample should occupy its own line.
  3. Each line should have fifteen elements, as described below.
  4. Elements should be separated from each other by white space (spaces or tabs).
  5. Something other than white space must be entered for each element. For example, if you have no Al measurements for a sample, you must enter "0" in the Al concentration and Al uncertainty positions.
In most cases, pasting directly from an Excel spreadsheet should satisfy the rules. An example of an acceptable input text block appears below.

The fifteen elements are as follows:

  1. Sample name. Any text string not exceeding 24 characters. Sample names may not contain white space or any characters that could be interpreted as delimiters or escape characters, e.g., slashes of both directions, commas, quotes, colons, etc. Stick to letters, numbers, and dashes.
  2. Latitude. Decimal degrees. North latitudes are positive. South latitudes are negative.
  3. Longitude. Decimal degrees. East longitudes are positive. West longitudes are negative.
  4. Elevation/pressure. Meters or hPa, respectively, depending on selection below.
  5. Elevation/pressure flag. Specifies how to treat the elevation/pressure value. This is a three-letter text string. If you have supplied elevations in meters and the standard atmosphere is applicable at your site (locations outside Antarctica), enter "std" here. If you have supplied elevations in meters and your site is in Antarctica, enter "ant" here. If you have entered pressure in hPa, enter "pre" here. Any text other than these three options will be rejected.
  6. Sample thickness. Centimeters.
  7. Sample density. g cm-3.
  8. Shielding correction. Samples with no topographic shielding, enter 1. For shielded sites, enter a number between 0 and 1.
  9. Erosion rate inferred from independent evidence. cm yr-1.
  10. 10Be concentration. Atoms g-1. Standard or scientific notation.
  11. Uncertainty in 10Be concentration. Atoms g-1. Standard or scientific notation.
  12. Name of Be-10 standardization. Text. Acceptable values for this parameter are given on this page.
  13. 26Al concentration. Atoms g-1. Standard or scientific notation.
  14. Uncertainty in 26Al concentration. Atoms g-1. Standard or scientific notation.
  15. Name of Al-26 standardization. Text. Acceptable values for this parameter are given on this page.
Note: Nuclide concentrations should already take account of carrier and process blanks.

Here is an example of an acceptable input text block. You can paste this in above to try a sample calculation.
     PH-1 41.3567 -70.7348 91 std 4.5 2.7 1 8e-5 123500 3700 KNSTD 712400 31200 KNSTD
     01-MBL-059-BBD -77.073 -145.686 712 ant 4.75 2.65 0.997 0 353000 8000 KNSTD 1940000 49000 KNSTD
     NH-1 57.968 -6.812 790 std 3 2.65 1 0 943000 28000 KNSTD 0 0 KNSTD
  
Here is an Excel spreadsheet containing example data that you can paste in above to try a sample calculation.