Fluid systems and fracture development during syn-depositional 1 fold growth: an example from the Pico del Aguila anticline, Sierras Exteriores, Southern Pyrenees, Spain.
Résumé
This paper reports an integrated, spatio-temporal analysis of the fracture-controlled paleo-fluid system in the Pico del Aguila anticline, a N-S trending fold located in the Sierras Exteriores, the southern front of the Spanish Pyrenees. Eight fracture sets (joints or faults) are recognized throughout the fold and are separated into a fracture sequence that is defined using field relationships and the remarkable temporal constraints offered by the syn-tectonic sedimentary deposits. This fracture sequence records a complex Paleocene to Early Oligocene structural evolution, including map-view, clockwise rotation and tilting of the fold axis. The geochemical analysis of calcite cements from the different mineralized fracture/vein sets reveals a compartmentalized fluid system during most of fold development. This initial paleofluid system was later perturbed when bending-related fractures associated with foreland flexure and outer arc extension triggered small-scale, vertical fluid migration. Fractures developed in shallow strata facilitated downward migration of surficial fluids that controlled the paleo-fluid system in the Late Priabonian/Stampian continental deposits. The study of the Pico del Aguila anticline depicts for the first time the evolution of a fluid system in a shallow, syn-depositional compressional setting, and results further strengthen the statement that fluids migrate vertically across stratigraphic boundaries take place during fold hinge-related deformation.
Fichier principal
Beaudoin_et_al_Fluid_systems_and_fracture_development_during_syn-depositional_fold_growth.pdf (4.98 Mo)
Télécharger le fichier
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...