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Article: Grenville-age pseudotachylite in the Lewisian: laserprobe ^sup 40^Ar/^sup 39^Ar ages from the Gairloch region of Scotland (UK)
- Article from:
- Journal of the Geological Society
- Article date:
- January 1, 2008
- Author:
CopyrightCopyright Geological Society Publishing House Jan 2008. Provided by ProQuest LLC. (Hide copyright information)
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Abstract:
Infrared laserprobe ^sup 40^Ar/^sup 39^Ar dating has been used to date pseudotachylite and host-rock minerals from a crush belt in the Lewisian basement of Scotland. It has revealed complexity in the pseudotachylite data that is attributable to the presence of refractory host-rock clasts and mineral fragments in the pseudotachylite. In conjunction with the host-rock mineral laserprobe ^sup 40^Ar/^sup 39^Ar data it has been possible to simplify the pseudotachylite data for the samples, and the preferred ages for these are: 980 ± 39 Ma, 999 ± 31 Ma and 1024 ± 30 Ma (2σ). These ages are the first record of Grenville-aged brittle deformation in the Lewisian. Further, this ...