UNIGE document Scientific Article
previous document  unige:87765  next document
add to browser collection
Title

Sediment provenance during Alpine orogeny: fluid inclusions and stable isotopes on quartz–calcite veins from detritic pebbles

Authors
Grosjean, Anne-Sabine
Gardien, Véronique
Dubois, Michel
Boulvais, Philippe
Pittet, Bernard
Published in Swiss Journal of Geosciences. 2016, vol. 109, p. 329-344
Abstract An innovative multidisciplinary approach was used on quartz–calcite veins that crosscut pebbles of several lithologies from the French South Alpine Foreland Basin to discern the source of detrital sediments. Microthermometric results indicate that inclusions contain low to moderate salinity (0.9–9.8 wt% eq. NaCl) fluids. Oxygen and carbon isotope compositions of quartz and calcite (d18O mean at ?24.1 and ?24.7 %respectively (VSMOW) and d13C from -1.1 to ?2.0 % (V-PDB)) are comparable with the composition of their host rocks (d18O from ?17 to ?24.3 % and d13C from -4 to ?1.4 %). The calculated d18O and d13C values of the fluid trapped in quartz and calcite range from ?9.3 to ?21.9 %, and from -2.6 to ?4.1 % respectively. These data suggest isotopic buffering of the fluid by the host rocks. Fluid trapping conditions were 105–185 MPa and 175–310 _C. Using a lithostatic gradient, the conditions of fluid entrapment correspond to a depth of vein formation from 4 to 7 km. Petrographic and geochemical data obtained on the host rocks, their veins and fluid inclusions suggest that the source of the conglomerates is the inner part of the Alps rather than reliefs surrounding the foreland basin. The study of fluid inclusions in veins provides a powerful and innovative approach to link the production of detrital sediments with tectonic events, to trace the provenance of conglomerates and to reconstruct the regional geometry of the drainage system.
Keywords ProvenanceOxygen and carbon isotopesWater–rock interactionsOligoceneWestern Alps
Identifiers
Full text
Article (Published version) (3.2 MB) - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://link.springer.com/10.1007/s00015-016-0228-1
Structures
Research group Sedimentology, Biostratigraphy and Micropaleontology
Citation
(ISO format)
GROSJEAN, Anne-Sabine et al. Sediment provenance during Alpine orogeny: fluid inclusions and stable isotopes on quartz–calcite veins from detritic pebbles. In: Swiss Journal of Geosciences, 2016, vol. 109, p. 329-344. https://archive-ouverte.unige.ch/unige:87765

113 hits

1 download

Update

Deposited on : 2016-09-26

Export document
Format :
Citation style :