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The fractal shape of sutured quartz grain boundaries: application as a geothermometer

✍ Scribed by J. H. Kruhl; M. Nega


Publisher
Springer
Year
1996
Tongue
English
Weight
816 KB
Volume
85
Category
Article
ISSN
0016-7835

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✦ Synopsis


Along grain boundaries of quartz from metamorphic and igneous rocks complex interfingering (sutures) may occur. Under the light microscope the lengths of the sutures range from approximately 10-1000 lxm. The sutured grain boundaries are statistically self-similar over one to two orders of magnitude. They represent fractals. Their mathematical counterpart are Koch curves which are developed after two to four iterations. The fractal (Hausdorff-Besicovitch) dimensions D of sutured quartz grain boundaries from different grades of m e t a m o r p h i s m are between ca. 1.05 and 1.30. The D-value decreases with increasing temperature during formation of the sutures. On a statistical basis, D can be used as a measure of this temperature and, therefore, as a deformation-related thermometer.