HR: 17:45h
AN: T14C-08 [Abstracts]
TI: Palaeogene Exhumation of the Pyrenean Orogen: Magnetostratigraphic and Thermochronological Constraints From the South-Central Pyrenees
AU: * Beamud, E
EM: betbeamud@ub.edu
AF: Grup de Geodinamica i Analisi de Conques, Facultat de Geologia
Zona Universitaria de Pedralbes, Barcelona, 08028, Spain
AU: Fitzgerald, P
EM: pgfitzge@syr.edu
AF: Department of Earth Sciences
Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States
AU: Muņoz, J
EM: jamunoz@ub.edu
AF: Grup de Geodinamica i Analisi de Conques, Facultat de Geologia
Zona Universitaria de Pedralbes, Barcelona, 08028, Spain
AU: Garces, M
EM: mgarces@ub.edu
AF: Grup de Geodinamica i Analisi de Conques, Facultat de Geologia
Zona Universitaria de Pedralbes, Barcelona, 08028, Spain
AU: Baldwin, S
AF: Department of Earth Sciences
Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States
AU: Webb, L
AF: Department of Earth Sciences
Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States
AU: Schwabe, E
AF: Department of Earth Sciences
Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States
AU: Cabrera, L
EM: lluis.cabrera@ub.edu
AF: Grup de Geodinamica i Analisi de Conques, Facultat de Geologia
Zona Universitaria de Pedralbes, Barcelona, 08028, Spain
AB:
The Pyrenees is an asymmetric, doubly vergent orogen formed by the collision between the European and Iberian
plates from late Cretaceous to Miocene times. The Pyrenean orogen comprises a central duplex structure of
Hercynian basement, the Axial Zone, which is flanked north and south by oppositely vergent fold and thrust belts
and associated foreland basins. The syntectonic continental conglomerates of the South-Central Pyrenees
record both the late stages of thin-skinned transport of the South-Pyrenean Central Units and the onset of
exhumation of the Pyrenean Axial Zone.
The magnetostratigraphic dating of the syntectonic conglomerates of Sis and La Pobla de Segur/Senterada
basins has yield a continuous record of the evolving orogenic system from 41 to 27 My (C18r to C9n). Apatite
fission track thermochronology on Axial Zone derived granite pebbles within these conglomerates has revealed 3
groups of detrital ages centred around 45, 60 and 27 My, with track lengths that reflect a first stage of slow cooling
followed by a period of rapid cooling. In the light of our results 4 stages in the tectonic evolution of the Pyrenean
orogen during the Palaeogene have been recognized, which involve variations in the amount and rate of
exhumation, as well as changes in the sedimentation rate, clast provenance and position of the water divide.
DE: 1140 Thermochronology
DE: 1520 Magnetostratigraphy
DE: 1525 Paleomagnetism applied to tectonics: regional, global
DE: 9606 Paleogene
SC: Tectonophysics [T]
MN: 2007 Fall Meeting