geoplay

The south-central Pyrenees provide some of the world's most instructive exposures for studying sedimentary facies. All types of clastic and carbonate environments in a continent to basin transition can be investigated, most of them within a short distance of the Tremp area.

The south-central Pyrenees are a natural laboratory that offers unique insights into orogenic processes. Tectonic and sedimentary interactions such as foreland basin formation and the mechanisms of basin fill can be studied both at outcrop and seismic scale.

Geological Introduction
The Pyrenees formed as a fold-thrust belt in Late Cretaceous to early Miocene times at the collisional boundary between the Iberian and European plates. Their geometry is fanlike with a central Hercynian antiformal stack flanked by thrust units of Mesozoic-Paleogene rocks detached above Triassic evaporites.

During the Cretaceous, a south-central Pyrenean rift basin recorded the deposition of rudist- and coral-bearing carbonate platforms. From Late Cretaceous to Eocene, a 7,000 m thick delta system filled a foreland deepening westward to the Atlantic ocean. The sedimentary facies evolve from fluvial sand belts to sheet turbidite sands, through deltaic/shoreface bars and slope channels, with minor intercalations of transgressive carbonates. Coarse alluvial fans were deposited from the latest Eocene to early Miocene.

Cross-section

A singular feature of the Pyrenean chain is the exceptionally well-preserved relationship between deformational structures and syntectonic sedimentation, allowing detailed studies of the interactions between tectonics and basin evolution.