August 1, 2005
Yale Fission-Track Programs here (0.7 Mb)

YaleFT is a ZIP file that contains a series of DOS programs for analysis of fission-track (FT) data. References are included below. The YaleFT distribution file is available at the web site above, which also has electronic reprints (PDF files) related to the use of these programs. Note that YaleFT does not include the Windows programs CLOSURE and BINOMFIT, which are distributed separately at the web site above.

Most of the YaleFT DOS programs were first written in the the early 1990’s, and have been upgraded in the following ways: (1) The calculation of exact confidence intervals in ZETAAGE using the algorithm of Sneyd (1984) (see Brandon, 1996, for details). (2) The use of the modified version of the probability density (PD) plot as outlined by Brandon (1996) in the GAUSSFIT and ZETAAGE programs. (3) The capability to generate files for (a) plotting histograms, (b) making PD plots for distributions of grain age, lag time, or spontaneous track density, (c) making radial plots for grain-age distributions, and (d) input to Jandel’s PEAKFIT program, a commercial program that produces results similar to GAUSSFIT and includes a graphical display of those results. (4) Modification of the file access routine to remedy problems with opening files for certain directory configurations. The problem was most commonly manifested when data files were stored in the root directory of a diskette. (5) Great flexibility with input files. The input file format used for ZFACTOR, ZETAAGE, GAUSSFIT, and BINOMFIT now allows comment lines which are flagged by a leading semicolon. The data input routine also ignores blank lines, which was major source of trouble for new users of the programs.

All programs are written in Microsoft Professional Basic 7.0, an advanced version of QBasic. The executables will run in a DOS window unders the WINDOWS operating system. To ensure broad compatibility, the programs have “plain-vanilla” design, and require no more than a monitor and a standard ASCII printer. Each program first presents a short overview plus a description of the format for any required data file. Data files are constructed using an ASCII-type editor (see examples below and in subdirectory DATA).

If you have any problems getting these programs to run on your computer, please send me by email a concise description of the problem plus a copy of the data file involved. I will attempt to fix any bugs and supply you with a modified version.

The FT programs and associated files provided in ZIP file called Yale_FT.zip. On extraction, the files should be organized into the following directory structure. (1) SOURCE original source code for all of the programs. (2) EXEC executable versions of the programs, which can be run at the DOS command line by simply typing the name of the program. (3) OUTPUT contains some files that show examples of the output of some selected programs. (4) DATA includes data files for Brandon and Vance (1992) and Garver and Brandon (1994a). Note that the directories in the path for the programs must have names that are no longer than 8 characters in length. The programs will not run if the directory names fail this specification.

The following programs are included:
BINOMFIT v. 1.8: An implementation of the binomial-peak fitting routine of Galbraith and Green (1990), which is used to estimate the ages of peaks or components in a mixed distribution of grain ages. (This program has been largely replaced by BINOMFIT for Windows, which does a automatic search for the full set of significant peaks). CHI2COMP v. 1.1: Determines the probability that improvement in fit due to the addition of a new peak to a best-fit model might be due to random chance alone. Used to determine the optimal number of peaks in BINOMFIT and GAUSSFIT (see Brandon, 1992, for discussion of F-ratio test). This testing is included in BINOMFIT for Windows. EXACT_X2 v. 1.0: Calculates ‘exact’ probabilities for the Chi^2 statistics, with the goal of accounting for small sample biases that arise with using Chi^2 distribution.

FLUENCE v. 1.1: Interpolates an effective fluence-monitor track density and uncertainty for a sample located at a known distance between two fluence monitors. Will also interpolate an effective Z factor if age standards are being used as fluence monitors.

FTCLOSE v. 1.0: Estimates (a) the FT closure temperature for the simple case of cooling through the partial annealing zone at a constant cooling rate, or (b) the temperature required to produce a specified percentage of annealing for a stepwise-thermal event. Brandon and Vance (1992) and Brandon and others (1997) provide examples of the output from this program. This program is largely superceded by the Windows program called CLOSURE (see web site), and by the DOS program called AGE2EDOT (see above).

GAUSSFIT v. 4.3: Gaussian peak-fitting routine of Brandon (1992). This program was originally called PEAKFIT. It is now largely superceded by the BINOMFIT programs, which perform better with FT data.

ZETAAGE v. 4.8: Calculates FT ages, with a special emphasis on handling grains with low track counts. Also includes options for producing output files that can be imported into a graphics program, such as EXCEL, to construct histograms, PD plots, and radial plots for grain-age distributions. New features provide options to calculate files for construction density plots for lag time or spontaneous track density, or the input file needed for Jandel’s PEAKFIT program. Many of the calculations done in ZETAAGE are now available in BINOMFIT for Windows. ZETAMEAN v. 1.0: Calculates grand weighted mean for estimates of zeta.

ZFACTOR v. 1.2: Determines zeta factor or Z factor for a single sample.

FAIR USAGE AND CITATIONS I have included the source code so that the calculations can be inspected. Comments in the code provide a detailed outline of the procedures and include references to the literature for further details, where appropriate. An important objective is to make it easier for others to experiment with the programs, with the hope that such efforts will lead to improvements. If you distribute modified versions of these programs, please also include a copy of the original versions or, at the very least, indicate my name and address as a source for the original programs. Also, clearly indicate in the modified program where the original version was obtained from and that the program has been modified. If you use these programs in an substantial way, then I request that you make note of this in any publications that results. The papers by Brandon (1992) and Brandon (1996) would be suitable references. Thank you for your interest. Please do not hesitate to contact me if you have any questions, comments, or criticisms.

DATA FORMAT The above programs use the following data files. Note that the extensions indicated below represent my preferences and are not required by the programs.
1) Files designate by the extension “.STD” are used by the ZFACTOR program to calculate a zeta or Z factor. An example from Garver and Brandon (1994b) is given in DATA.
2) Files designated by “.FTA”, “.FTZ”, or “FTS” represent FT data from the external detector method for apatite, zircon, and sphene, respectively. These files are used by the ZETAAGE, GAUSSFIT, and BINOMFIT programs.
3) Files designated by the extension “.PK”, are used by GAUSSFIT to describe a group of best-fit peaks, each of which is represented by its mean age, standard deviation in Z units, and number of grains. An example from Garver and Brandon (1994b) is given in DATA.
4) Files designated by the extension “.LST” are used to operate the ZETAAGE program in a batch mode. An example from Brandon and Vance (1992) is given in DATA. The GAUSSFIT program can also be operated using a batch file with a format somewhat like that used by ZETAAGE. No example is given of this type of file.
5) Standard output for the GAUSSFIT program can be redirected to a file that is given the extension “.GFT”.
6) Standard output for the BINOMFIT program can be redirected to a file that is given the extension “.BFT”.
7) The ZETAAGE program can output several different types of files. Examples of the .ASC, .PRB, and .PLT files are given in OUTPUT.
8) The AGE2EDOT program provides its output in a file with an extension .DAT.
9) “.ASC”–Files with this designation contain the standard output of ZETAAGE in ASCII form as redirected from the printer.
10) “.PRN”–Files with this designation contain the probability density curve in a format that can be used as input for the Jandel PEAKFIT program, a commercial program that will produce results similar to the GAUSSFIT. Note that Jandel’s PEAKFIT provides a graphical display of the fitting procedure, which is especially useful when first learning to fit peaks to FT data.
11) “.PRB”–Files with this designation are ASCII files of the data needed to construct a histogram and CPD plot for a grain-age distribution. ZETAAGE includes the option to add CPD plots of individual peaks to this output file. The .PRB file is designed to be directly imported into a spreadsheet or graphics program.
12) “.PLT”–Files with this designation are ASCII files of data needed to construct a radial plot. The .PLT file is designed to be directly imported into a spreadsheet or graphics program.
13) Standard output for the EXACT_X2 program can be redirected to a files that has a default extension of .CHI.

The formats for the STD and .FT_ files are described in more detail below.
Used to calculates zeta or Z factor for fission-track data using an age standard.
Input file structure should be as follows:
Line 1: Title for data set (describe method, age standard, and glass standard).
Line 2: Age (Ma) and standard error (My) of age standard; separate values with commas.
Line 3: Separate all values with commas.
ZETA-METHOD: Track density (track/cm^2) and relative standard error (%) for fluence monitor.
Z-METHOD: Enter the following for this line: 1, 0.
Line 4: Area of 1 counting square (cm^2).
Line 5 and on: Spontaneous tracks, induced tracks, number of squares for each grain; data values can be separated by either spaces or commas.
NOTE: Input routine skips comment lines (first character=semicolon) and blank lines. Constants and method are after Hurford and Green (1983). Total decay constant for 238U, yr^-1, LamdaD = 1.55125E-10 Geometry factor = 0.5

27.9, 0.35
2.005e05, 2.19
175 124 40
222 156 34
; you can place comments in the file by beginning the
; line with a semicolon
; note that blank lines are ignored
138 185 40
214 236 61
250 248 56
249 264 49
361 335 64
348 325 72
148 151 30
357 292 50
185 165 33
219 193 36

Input file structure should be as follows:
Line 1: Title for data set
Line 2: This line is flagged by making the first value negative. All values on this line should be separated by commas.
ZETA METHOD: Effective track density (tr/cm^2) and the relative standard error (%) for the fluence monitor, and the effective uranium concentration (ppm) of the monitor standard.
Z METHOD: Enter line as: -1, 0, 0.
Line 3: All values should be separated by commas.
ZETA METHOD: Zeta factor (yr cm^2/tr), standard error (yr cm^2/tr), counter square size (cm^2).
Z METHOD: Z factor (yr), standard error (yr), counter square size (cm^2).
Line 4 and on: For each grain, enter the measured spontaneous and induced tracks, and the number of squares for the area counted. Data values can be separated by spaces or commas.
NOTES: To merge another dataset, repeat lines 2 and on. Input routine skips comment lines (first character=semicolon) and blank lines. Methods and fission track constants are after Hurford and Green (1983). Total decay constant for 238U (yr^-1) = 1.55125E-10 Geometry factor = .5

-1.9788e5, 2.09, 12.3
316.7, 6.7, 8.354e-7
163 38 32
; use a semicolon to insert a comment; comments and
; blank lines are ignored
143 70 40
215 82 50
184 74 50
139 41 39
126 58 36
309 135 60
380 116 35
119 53 15
292 65 15
259 48 9
199 72 21
202 86 34
213 92 50
381 81 45
242 101 21
757 137 80
431 169 40
472 201 48

Bardsley. W.E., 1983, Confidence limits for fission-track dating. Mathematical Geology, v. 15, p. 649-658.

Brandon, M.T., 1992, Decomposition of fission-track grain-age distributions. American Journal of Science, v. 292, p. 535-564.

Brandon, M.T., 1996, Probability density plot for fission-track grain-age samples. Radiation Measurements, v. 26, p. 663-676.

Brandon, M.T., and Vance, J.A., 1992, Tectonic evolution of the Cenozoic Olympic subduction complex, Washington State, as deduced from fission-track ages for detrital zircons. American Journal of Science, v. 292, p. 565-636.

Brandon, M. T., Roden-Tice, M. K., and Garver, J. I., 1998, Late Cenozoic exhumation of the Cascadia accretionary wedge in the Olympic Mountains, northwest Washington State: Geological Society of America Bulletin, v. 110, p. 985-1009.

Chapman, D.G., 1952, On tests and estimates for the ratio of Poisson means. Annals of the Institute of Statistical Mathematics (Tokyo), v. 4, p. 45-49.

Galbraith, R.F., 1988, Graphical display of estimates having differing standard errors: Technometrics, v. 30, p. 271-281.

Galbraith, R.F., 1990, The radial plot: graphical assessment of spread in ages. Nuclear Tracks and Radiation Measurements, v. 17, p. 207-214.

Galbraith, R.F., and Green, P.F., 1990, Estimating the component ages in a finite mixture: Nuclear Tracks and Radiation Measurements, v. 17, p. 197-206.

Garver, J.I., and Brandon, M.T., 1994a, Fission-track ages of detrital zircon from Cretaceous strata, southern British Columbia: Implications for the Baja BC hypothesis. Tectonics, v. 13, p. 401-420.

Garver, J.I., and Brandon, M.T., 1994b, Erosional denudation of the British Columbia Coast Ranges as determined from fission-track ages of detrital zircon from the Tofino basin, Olympic Peninsula, Washington. Geological Society of America Bulletin, v. 106, p. 1398-1412.

Hurford, A.J., and Green, P.F., 1983, The zeta age calibration of fission-track dating: Isotope Geoscience, v. 1, p. 285-317.

Hurford, A.J., Fitch, F.J., and Clarke, A., 1984. Resolution of the age structure of the detrital zircon populations of two Lower Cretaceous sandstones from the Weald of England by fission track dating. Geological Magazine, 121, p. 269-277.

McCullagh, P., and Nelder, J.A., 1983, Generalized Linear Models. London, Chapman and Hall, 261 p.

Silverman, B.W., 1986, Density estimation for statistics and data analysis. London, Chapman and Hall, 175 p.

Sneyd, A.D., 1984, A computer program for calculating exact confidence intervals for age in fission-track dating. Computers and Geosciences, v. 10,
p. 339-345.

Mark T. Brandon Department of Geology and Geophysics Yale University P.O. Box 208109 New Haven, CT 06520-8109