At 10:36 AM 2000/10/31 +0100, Pascal Cortes wrote:
>Hi all,
>I have with me an Excel file with more than 1.000 fracture data (strike,
>dip) and their related bedding dip measurement. I'd like to perform (on
>Excel) an automatic dip correction (bedding brought back to horizontal) for
>each individual fracture...
Johannes Duyster's marvelous StereoNett freeware can do this easily:
http://homepage.ruhr-uni-bochum.de/Johannes.P.Duyster/stereo/stereo1.htm
After unzipping, the exec file takes ~740k of memory and the help file
takes ~240k. It is easy to learn and easy to use. Structural attitudes
can be cut-and-pasted from your textfile or database directly into the
StereoNett menu, in a 3-column format separated by spaces, e.g.,
035 21 P
247 78 P
...
where 'P' or 'p' identifies planar data and 'L' or 'l' identifies linear data.
Planar data must be tabulated the European way, as dip-azimuth
(right-hand-rule strike-azimuth plus 90 degrees) and dip angle, trusting
the software to compute and plot the pole to each plane. Highlight all the
data you want to rotate, and then click on 'Rotate' in the 'Data' menu. A
new menu appears in which you can specify the trend and plunge of the axis
of rotation (in this case just the strike-line of the bedding) and the
angle and sense of rotation. When you hit the 'enter' key, all the
highlighted numerical attitudes will be rotated. You can then view them in
equal-area projection, contour them, do statistics etc.
Cheers, Dugald
Dugald M Carmichael Phone/V-mail: 613-533-6182
Dept of Geological Sciences and Geological Engineering
Queen's University FAX: 613-533-6592
Kingston ON K7L3N6 E-mail: [log in to unmask]
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