*Isoplot* is BGC’s Visual Basic Add-in for Microsoft’s Excel ® for data analysis and graphical presentation of geochronology, earth science and other radiogenic isotope data only.

BGC’s *Isoplot* is not the *Isoplot®* for analysis of any measuring system as described at http://www.shainin.com/. BGC is not affiliated with Red X® Holdings, LLC. *Isoplot®* is a registered trademark of Red X® Holdings, and is licensed to Shainin ® LLC.

*Isoplot* is a flexible tool for the mathematical and graphical interpretation of radiogenic-isotope data, especially as applied to geochronology.

*Isoplot 3.7* and *Isoplot 4.1* are “Add-In” programs that run only under *Windows Excel *versions 2003 and earlier (*Isoplot 3.7*), or only under *Excel* versions 2007 and 2010 (*Isoplot 4.1*). No versions of* Isoplot* can be run as a stand-alone program.

*Isoplot 3** is not compatible with either Excel 200*7 or *Excel* *2010*. If you must use *Excel* *2007 *or *Excel* *2010*, request a copy *Isoplot* *4*, which is compatible with *Excel 2007/2010* __only__. *Isoplot 4* has no more functionality than *Isoplot 3.7*, and somewhat *less* flexibility. Expect a speed penalty of up to a factor of 10 when using *Excel* *2007/2010*.

*Isoplot* can:

- Calculate and plot classical isochrons (Rb/Sr, Sm/Nd, U/Pb, Re/Os, Lu/Hf…);
- Construct U-Pb concordia plots and calculate ages using conventional concordia intercepts, the “Concordia Age” algorithm, 3-D planar concordia intercepts, or 3-D linear (“Total U/Pb”) isochrons;
- Calculate uranium-series isochron ages using 3-D or 2-D isochrons and construct 230Th/238U-234U/238U evolution curves and isochrons;
- Plot Ar-Ar step-heating diagrams and find the statistically-best plateau steps and age;
- Combine Ar-Ar isochron with Ar-Ar step-heating diagrams to obtain the logically optimum combination of both;
- Use simple Bayesian constraints Improve the estimates and error-assignments for a package of stratigraphically-constrained radiometrically-dated units whose ages overlap within errors (with a special variant for 230Th/U ages);
- Construct single-stage growth-curves for plots of common-Pb data;
- Construct cumulative-probability / histogram plots and linearized-probability diagrams;
- Calculate both conventional (analytical-error weighted) and robust (nonparametric) x-y regressions for “classical” and Pb-Pb isochrons;
- Deconvolute mixtures of components having Gaussian error-distributions using the Sambridge-Compston approach;
- Calculate and construct plots for either error-weighted or robust (nonparametric) averages of a single variable;
- Plot curves for almost any function;
- Provide Monte Carlo errors as well as asymptotic (first-order) errors for most linear regressions, isochrons, and concordia-intercept solutions;
- Extract reliable ages and errors from complex suites of Phanerozoic single-zircon dates;
- Expand the number of
*Excel*functions by more than 50, including many functions for radiogenic-isotopes (including 16 for U/Pb and 8 for 230Th-234U-238U alone).

*Isoplot* is available without charge.

Files for Downloading

Isoplot3.75 files.zip (contains all of the above files plus the add-in itself)