Foreland Basin Syntectonic Sedimentation - Southern Pyrenees, Spain
The course objective is to demonstrate the evolution from continental through shallow marine to slope and submarine fan sedimentation during formation of a foreland basin with syntectonic sedimentation in adjacent but sequential sub-basins associated with evolving thrust fronts during the Pyrenean orogeny.
Starting and finishing in Barcelona, the following basins are visited in turn: the Upper Palaeocene-Lower Eocene Ager Basin; the Eocene Tremp-Grauss and Ainsa Basins; Upper Eocene-Oligocene Jaco Basin; and finally the Oligo-Miocene Ebro Basin. Impressive panoramic views are available of the various sedimentary sequences to be observed in detail. Large-scale tectonic elements that controlled the sedimentation are evident. The clastic dominated sequences essentially record the westwards deepening and progressively marine influenced foreland basin evolving as the Pyrenean range developed from Eocene onwards, although the more southerly and younger Ebro Basin succession is spectacularly dominated by alluvial fan and fluvial sediments.
Course bases: Barcelona, Tremp, Grauss, Ainsa, Broto, Barcelona.
- Cross the External Sierras; traverse the southern edge of the Ager Basin and the Monsech Thrust sheet en route to Tremps.
- Impressive panoramic view of the Ager Basin from Puerto de Ager Refugio.
- Ager basin-fill sediments in a footwall syncline.
- Estacion de Ager: syntectonic unconformity.
- Eocene Tremp-Grauss Basin: incision and fluvial Castisent Sandstone
- Puerte de Montanana: meandering stream point bar deposits
- Aren: prograding low- and high-stand wedges of Maastrichtian Aren Sandstone
- Serraduy: Large-scale tidal cross-bedded Alveolina limestone
- La Puebla de Roda: Oligo-Miocene palaeovalley fill. Eocene Roda Sandstone with possible tidal reworking of delta front
- La Colomina: oyster-bearing estuarine sediments with tidal channel erosion in Montanana sequence
- South of Grauss: back-shed alluvial fan conglomerates with southern provenance from developing External Sierras
- Eocene incised valley deposits
- Murillo: Cotiella-Monsech thrust sheet created by inversion and view stop of Castisent Sandstone
- Perarrua: stacked coarsening-up, storm-dominated marine shoreface sediments of Santa Liestra Fm.
- Ainsa Basin, Formigales: slope sediment collapse; slide block.
- Ainsa: channelled turbidites
- Boltana antincline
- Jaco Basin, Linas de Broto: thin basin plain calc-turbidites and mega-bed turbidites (<=200m thick)
- Castillo de Jaco area: slump/olistostrome and inverted mega-bed turbidite
- Ebro Basin, Riglos: basin margin, Oligo-Miocene alluvial fan conglomerates associated with emergent thrust front of External Sierras
- Piraces: Huesa system medial basin, low-sinuosity fluvial sheet and ribbon sands spectacularly exposed in canal cuts.
Petroleum geologists, geophysicists, reservoir engineers, sedimentologists, stratigraphers