Fluid migration through thrust faults in the Helvetic nappes (Western Swiss Alps)

Détails

ID Serval
serval:BIB_DA7F2C021D68
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Fluid migration through thrust faults in the Helvetic nappes (Western Swiss Alps)
Périodique
Contributions to Mineralogy and Petrology
Auteur⸱e⸱s
Kirschner D.L., Masson H., Sharp Z.D.
ISSN-L
0010-7999
Statut éditorial
Publié
Date de publication
1999
Peer-reviewed
Oui
Volume
136
Pages
169-183
Langue
anglais
Résumé
The delta(18)O, delta(13)C and Sr-87/Sr-86 values of calcite and organic
matter were measured for carbonate mylonites from numerous thrusts in
the Helvetic Alps. Carbonate mylonites in most of the thrusts retain
essentially unaltered protolith delta(18)O and delta(13)C values,
consistent with there having been little to no advection of isotopically
distinct fluid through these faults. Only carbonate mylonites from the
basal thrusts of the largest nappes have delta(18)O and/or delta(13)C
values that differ from those of their protoliths. The zone of isotopic
alteration/exchange is confined to c. 10 to 20 meters of these fault
contacts. We propose the fluids that migrated through these faults
contained variable amounts of organically derived carbon and radiogenic
strontium, and were probably derived from dewatering of the sedimentary
rocks and prograde metamorphic reactions in the nappes' root zones.
Apart from the basal thrusts of the largest nappes that behaved as
narrow, laterally extensive conduits for fluids, there is little
isotopic evidence that large quantities of fluids passed through most of
the carbonate-hosted thrusts in the Helvetic Alps.
Création de la notice
07/12/2012 14:51
Dernière modification de la notice
20/08/2019 15:59
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