The Pyrenees are an intracratonic mrogen which formed between late Cretaceous and Early Miocenes as a result of convergent motions between the Afro-Iberian and European plates. No large-scale subduction of ocean crust preceded the formations of the Pyrenees and no magma formed, yet recent work indicates 150 km of massive crustal shortening. The recent ECORS seismic section has allowed a detailed sequence of events to be developed to explain these data. If correct, the proposed sequence of events has importance for the tectonics of the western Mediterraneans. The purpose of this project is to test these ideas by using Fission Track geochronometry to help discriminate between the different uplift patterns predicted. Results should help in understanding compressional collisions where the amount of seafloor subduction has been minor.