Kinematic Evolution of the Southern Ebro Foreland Basin

David L. Barbeau¹, Nick Swanson-Hysell², Ellen Schaal², Kate Stalker², Peter DeCelles³, Joseph Kirschvink⁴, and Bereket Haileab^2
1 University of South Carolina, Columbia, SC
² Carleton College, Northfield, MN
³ University of Arizona, Tucson, AZ
⁴ Caltech, Pasadena, CA

A complete Paleocene(?)-Oligocene terrestrial foreland basin succession is preserved in the southwestern Catalán Coastal Ranges and the adjacent southern Ebro Basin of northeastern Spain. Composed of pedogenic, lacustrine, fluvial, and alluvial-fan strata, this succession contains lithofacies characteristic of the forebulge, foredeep, and wedge-top depozones of recent foreland basin models. Whereas the appearance of conglomerate within the succession has been used to date the onset of orogenesis caused by uplift of the Pyrenean, Iberian and Catalán Coastal Ranges, pedogenic and fine-grained lithofacies preserved in the lower part of the study interval suggest that these strata may be the result of forebulge development, and that the timing of tectonic onset may need to be revised downward. However, the study interval has a disproportionately thin foredeep succession in comparison to other well-studied foreland basins. Using flexural modelling, and geochemical, lithostratigraphic & magnetostratigraphic data, we evaluate (a) overfilled basin, (b) wedge propagation, (c) competing load, and (d) classical tectonic models for the Paleogene succession of the southern Ebro basin. Re-evaluation of the southern Ebro succession has implications for the kinematic evolution of basin-fringing thrust belts, and Cenozoic plate tectonic reconstructions of the western Mediterranean, and identifies an important terrestrial locality for the investigation of dramatic Paleocene-Eocene and Eocene-Oligocene paleoclimatic events.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005