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Article: Recrystallization or cooling ages: in situ UV-laser ^sup 40^Ar/^sup 39^Ar geochronology of muscovite in mylonitic rocks
- Article from:
- Journal of the Geological Society
- Article date:
- July 1, 2004
- Author:
CopyrightCopyright Geological Society Publishing House Jul 2004. Provided by ProQuest LLC. (Hide copyright information)
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Abstract:
The intra-grain ^sup 40^Ar/^sup 39^Ar age distributions of muscovite from grecnschist-facies mylonite zones are shown to be sensors of metamorphic history. Textures, compositions and in situ UV-laser ablation ^sup 40^Ar/^sup 39^Ar data from two extensional shear zones demonstrate that cooling ages can be distinguished from nco- or recrystallization ages. Deformed muscovite porphyroclasts and recrystallized shear band muscovite from the Pogallo Shear Zone (Ivrea Zone, southern Alps) reveal variable intra-grain ^sup 40^Ar/^sup 39^Ar ages with internal age variations of more than 65 Ma. The wide range of ^sup 40^Ar/^sup 39^Ar ages within compositionally homogeneous grains is ...
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Article: High grade shear zone extended at million mountain ...
M2 Presswire;
June 9, 2006 ;
700+ words
... ... Coeur Minerals Ltd.: High grade shear zone extended at million mountain ... targeting extensions to the high grade shear zone intersected by previously reported ... holes MM01-05 and 02-05. The shear zone intercept in drill hole MM01 ...
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