PAQUETTE , Jean-Louis

Carbonatites are mantle-derived rocks associated with rare earth element deposits and their origin is debated. The majority of carbonatites are found in proximity to old continental crust and generally exhibit more geochemically enriched Sr and Nd isotopes relative to the prevalent mantle, with only a few known carbonatite occurrences found in...

We investigate the age and chemical composition of the granitic basement of the Gassane borehole in Senegal. 40 Ar/ 39 Ar and U/Pb dating yield ages of 200.3 ± 2 Ma and 198.4 ± 1.8 Ma, respectively, demonstrating that it is not related to the Variscan orogeneis as previously thought. Rather, we suggest that this granite derived from crustal...

This study presents the first geochronological results on basement rocks from the Penguin-Bage-Webb (PBW) domain located east of the Neoarchean-Paleoproterozoic Terre Adélie craton, Antarctica. Investigated samples are paragneiss xenoliths hosted within early Paleozoic granitoids, which were emplaced during the Ross orogeny. Zircon UPb dating...

U-Pb and Th-Pb dating of monazite from hydrothermal quartz veins ("alpine veins") from the Lauzière massif (North Belledonne) together with Ar / Ar ages of adularias from the same veins constrain the age of the last tectono-metamorphic events that affected the External Crystalline Massifs (ECM). Ages obtained are surprisingly young. The study...

The Souttoufide belt is situated between the High-Atlas in the north, the Mauritanides in the south and the West African Craton as well as the Tindouf basin in the east. Thus, this belt is a part of the West African fold belt system which surrounds the West African Craton. Outcrops occur only in three areas, while the rest of the Souttoufide...

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