Sebastien Castelltort1, François Guillocheau1, Thierry Nalpas1, Delphine Rouby1, Cécile Robin2, Marc Urreiztieta3, Isabelle Coutand1
(1) University of Rennes, Rennes, France
(2) University of Paris VI, Paris, France
(3) Total-Fina-Elf, Pau, France
ABSTRACT: Tectonically Induced Distorsion Of Stratigraphic Cycles. Example Of The Arguis Anticline In The South Central Pyrenees (Spain)
Short wave-length growth tectonic structures, like kilometric growth folds, generate local variations in the subsidence field, and therefore potential perturbations of the stratigraphic signal (Accommodation/Sedimentation).
In order to assign this problem, we present a sequence stratigraphic analysis of the Eocene deltaic syntectonic deposits of the Arguis anticline, in the southern Pyrenees (Spain). The study, based on 2D measurements of accommodation and sediment supply, shows that one expression of those perturbations can be a distorsion of the syntectonic stratigraphic cycles i.e a variation in the symmetry of the cycles, in time and/or thickness.
Theoretical explanation for this type of distorsion allows us to propose it as an additionnal tool for predictive sequence stratigraphy in syntectonic sedimentation settings. Our work also shows that non-uniform variations of the thickness of growth strata can occur with a constant rate of development of the structure, related to the cyclic nature of the sedimentary record. This should be taken into account for reverse modeling of growth structures.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado