Short Description

The data reduction program ArArCALC includes four different utilities that are executed within Microsoft Excel 2000-XP-2003-2007-2011: (1) curved or linear data regression, (2) blank evolution analysis, (3) age calculation, (4) J-value calculation, (5) air shot calculation and (6) age recalibration.

These utilities fully interact with each other providing a high level of automation. Besides ArArCALC allows for editing of all the input data, parameters and constants used in the calculations at every level of the program and at all times. This provides the needed flexibility when using ArArCALC online during mass spectrometry and when not all input data are available or final (J-values, blank intensities, and so forth). The new File Watch functionality will allow you to auto-calculate data files that just have been acquired on your mass spectrometer. The same experiments can also be recalculated offline after editing the changed input data. ArArCALC never requires you to "recalculate" your ⁴⁰Ar/³⁹Ar ages from scratch. ArArCALC now also supports data files acquired on the state-of-the-art multicollector mass spectrometers.

The ArArCALC program comes with Help Files written in HTML that are accessible through your browser and from within the software itself.

Each Microsoft Excel workbook produced by ArArCALC includes five separate worksheets, which contain:

• Multiple data tables (including the relative abundances table recommend by Renne et al. 2009)
• Age and K/Ca plateau diagrams
• Normal and inverse isochron diagrams

The data tables contain all the necessary input and output data for the ⁴⁰Ar/³⁹Ar age calculations. The input data can be edited during every stage of the data reduction. The output data reflect all the data represented in the four diagrams and all argon data needed to judge the outcome of your experiments and calculations.

Another advantage of using Excel workbooks lies in the fact that these files can be readily distributed amongst users of your lab, but also between different (international) laboratories.

The program ArArCALC is characterized by many useful properties and functions. Down here you will find an (incomplete) listing:

• Complete error propagation including external errors.
• Ages can be recalibrated all the way back to the primary K-Ar standards.
• Degassing patterns for all argon components can be viewed in an easy-to-use dialogbox.
• Density probability curves and mixture modeling (Sambridge & Compston 1994) are now combined in a single easy-to-use dialogbox.
• Weighted and unweighted YORK2 fit to calculate isochrons.
• Data tables and charts within "one" Excel workbook
• Generic input filter to read most types of (raw) mass spectrometry data files, including individual readings and multicollector formats.
• All input data are editable during and after data reduction.
• The user can now apply linear, exponential or power law mass discrimination corrections.
• Blank, air shots and flux monitor measurements are now saved to a local database.
• Air calculations can now be performed and saved in a separate *.AIR calculation file.
• Error ellipses in isochron diagrams.
• Report errors in 1 or 2 sigma.
• Report ages in Ka, Ma or Ga units.
• All constants are set in preferences dialogboxes.
• Summaries for the plateau, isochron and total fusion ages.
• Get additional statistics on the age plateaus, including kurtosis, skewness and slope.
• Password protection of irradiation files and preferences.
• Set your own project names and irradiation constants.
• Flag out data points with one-mouse click.
• Calculate ages online and offline mass spectrometry.
• Import multiple experiments in one Excel workbook and overlay these onto one each other in the age plateau diagram.
• Overlay the K/Ca data on top of the age plateau diagram.
• Toggle between age and J-value calculations.
• Perform lunar age calculations.
• Help files are available in HTML format.
• Data can be reduced using exponential, parabolic and linear fits, or by simply averaging.
• Interpolated procedure blanks can be calculated in an easy-to-use dialogbox.
• Custom sort the tables in ascending and descending order.
• Copy all charts to the clipboard to easily paste it as a vector-based diagram in your favorite drawing program.
• Generate empty age calculation templates in which you can fill in "old" data and recalculate the ages.
• Users are warned about new versions during start up of ArArCALC, if a new version is available on the EarthRef.org server.
• Age data now can be exported to XML and uploaded to the online GEOCHRON portal.
• User can add Metadata about the age results, standard used, sample, location and laboratory.
• User can request an IGSN number from within ArArCALC which required for uploading to GEOCHRON.
• Export for publication now allows for users to pick out the tables and plots to include in the editable Excel files, including a compact mode for placing all tables and diagrams on one page and a special EarthTIME mode for providing an output with a minimum number of recommended tables and plots.
• Export for publication allows you to save age and air shot data in PDF format (if you have Adobe Acrobat installed).