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Palaeomagnetic dating of widespread remagnetization on the southeastern border of the French Massif Central and implications for fluid and Mississippi Valley-type mineralization

B. Henry·H. Rouvier·M.L. Goff·D. Leach·J.-C. Macquar·J. Thibieroz·Michael T. Lewchuk
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Abstract

Palaeomagnetic dating techniques have been applied to determine the age of fluid migration that produced the Mississippi Valley-type (MVT) Pb-Zn-Ba-F deposits in the Ce??vennes region of southern France. 15 sampling sites in two gently deformed areas around the Largentie??re and Croix-de-Pallie??res mines on the Ce??vennes border were selected for palaeomagnetic study. They yielded a very well-defined direction of remagnetization corresponding to an Early-Middle Eocene age. This remagnetization cannot be related to the formation of magnetic as a result of the transformation of smectite to illite because the latter has been well dated as a Mesozoic event. The magnetic overprint in this area is related to a chemical phenomenon during fluid migration. The age of remagnetization corresponds to a major uplift in the Pyre??ne??es mountains, located to the south of the Ce??vennes. This implies that fluid migration occurred from the south to the north as a result of hydraulic head established in the Pyre??ne??es orogenic belt during orogenesis and suggests that the MVT deposits in the Ce??vennes region formed from a gravity-driven fluid system as described by Garven & Freeze (1984a,b).

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B. Henry, H. Rouvier, M.L. Goff, D. Leach, J.-C. Macquar, J. Thibieroz, Michael T. Lewchuk. 2001. Palaeomagnetic dating of widespread remagnetization on the southeastern border of the French Massif Central and implications for fluid and Mississippi Valley-type mineralization. https://doi.org/10.1046/j.0956-540x.2001.01382.x

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