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Simultaneous resetting of the muscovite K‐Ar and monazite U‐Pb geochronometers: a story of fluids
Author(s) -
Tartèse Romain,
Ruffet Gilles,
Poujol Marc,
Boulvais Philippe,
Ireland Trevor R.
Publication year - 2011
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2011.01024.x
Subject(s) - monazite , geology , muscovite , zircon , overprinting , geochemistry , radiogenic nuclide , mineral , titanite , metamorphic rock , mineralogy , paleontology , quartz , mantle (geology) , materials science , metallurgy
Terra Nova, 23, 390–398, 2011 Abstract Although water is ubiquitous in the continental crust, its effect on geochronometers through mineral reequilibration is rarely taken into account. Herein, we present 40 Ar/ 39 Ar analyses on muscovite and U‐Pb isotopic data on zircon and monazite from a Variscan syn‐tectonic granite from western France. Both the K‐Ar in the muscovite and U‐Pb in the monazite isotopic systems were hydrothermally reset, whereas the U‐Pb radiogenic system in most of the zircons was unaffected and dates the granite emplacement age. Titanium chemical maps obtained on muscovites from various dated samples display a spectacular overprinting of their magmatic zoning resulting from increasing fluid‐rock interaction. These results reiterate the need to combine geochronological data with petrological, mineralogical and geochemical studies to accurately interpret ages obtained in this type of geodynamical settings.